!WARNING! Please be aware that some software differs with the original Linux Mint, since we used Ubuntu with Unity as the base system, but that's something you'll have to live with or change yourselves.
DebOrphan can delete orphans... which aren't excactly orphans. That's why the deborphan command is commentted. To use the deborphan part, remove the "#" before the "sudo apt-get purge `deborphan` command.

Some of you have noticed that Linux Mint doesn't have an Alternate installer available and aren't planning to support or create one.
Also ubuntu dropped the alternate cd as of 14.04 (or perhaps earlier?). So, how can we install Linux Mint on older PCs who can't handle the graphical installer, or do not support PAE?

Step 1a: Download and burn a ubuntu server 14.04 iso to a cd/dvd (The 86x/32 bit server edition can ONLY be download over here: http://releases.ubuntu.com/14.04/).
Step 1b: *OPTIONAL* Download the Ubuntu Desktop File iso prepared by yours truly and burn it to an cd/dvd as well: http://dl.dropbox.com/u/56456194/linux/ubuntudesktop.iso or http://dl.dropbox.com/u/56456194/linux/ubuntudesktop_x64.iso for 64 bit.

Step 2: Install Ubuntu Server 14.04 according to your wishes. If needed use the forcepae option in the boot menu according to this page: https://wiki.ubuntu.com/Lubuntu/AdvancedMethods. If you can't boot, use a livecd/liveusb to edit your grub options with forcepae (if this still doesn't work you're out of luck I'm afraid).

Step 3: Use "sudo tasksel" to delete the basic server package and purge tasksel with "sudo apt-get purge tasksel"

Step 4: Install the Ubuntu Desktop with "sudo apt-get install ubuntu-desktop", or if you did Step 1b insert the Ubuntu Desktop File cd, mount it and use "sudo dpkg -i /[MOUNTPOINT]/*.deb" (ignore the errors).

Step 5: After the installation of the desktop, use the script provided here (you can change the repositories if you want to), when asked choose MDM and for Pete's sake, run this as root!:

START OF SCRIPT

#!/bin/sh

# This script is based on the tutorial of Jeff Shaffner, for more info
# Go to: http://jeffshaffner.wordpress.com/2012/09/27/how-to-convert-ubuntu-12-04-to-linux-mint-13/

set -e

rm /etc/apt/sources.list
touch /etc/apt/sources.list
echo "#deb cdrom:[Linux Mint 17 _Qiana_ - Release amd64 20140530]/ trusty contrib main non-free" >> /etc/apt/sources.list

touch /etc/apt/sources.list.d/getdeb.list
echo "# deb http://archive.getdeb.net/ubuntu trusty-getdeb apps" >> /etc/apt/sources.list.d/getdeb.list

touch /etc/apt/sources.list.d/official-package-repositories.list
echo "deb http://ftp.nluug.nl/os/Linux/distr/linuxmint/packages qiana main upstream import" >> /etc/apt/sources.list.d/official-package-repositories.list
echo "" >> /etc/apt/sources.list.d/official-package-repositories.list
echo "deb http://extra.linuxmint.com qiana main" >> /etc/apt/sources.list.d/official-package-repositories.list
echo "" >> /etc/apt/sources.list.d/official-package-repositories.list
echo "deb http://mirrors.mit.edu/ubuntu trusty main restricted universe multiverse" >> /etc/apt/sources.list.d/official-package-repositories.list
echo "deb http://mirrors.mit.edu/ubuntu trusty-updates main restricted universe multiverse" >> /etc/apt/sources.list.d/official-package-repositories.list
echo "" >> /etc/apt/sources.list.d/official-package-repositories.list
echo "deb http://security.ubuntu.com/ubuntu trusty-security main restricted universe multiverse" >> /etc/apt/sources.list.d/official-package-repositories.list
echo "deb http://archive.canonical.com/ubuntu trusty partner" >> /etc/apt/sources.list.d/official-package-repositories.list

apt-get --quiet update
apt-get --yes --allow-unauthenticated install linuxmint-keyring
wget http://dl.dropbox.com/u/56456194/linux/official-package-repositories.pref -q -O /etc/apt/preferences.d/official-package-repositories.pref
apt-get update
apt-get --yes purge software-properties-* python3-software-properties apturl-common
apt-get --yes install linux-kernel-generic
apt-get --yes install mdm mint-meta-core mint-meta-cinnamon deborphan
apt-get --yes purge unity* xul-ext-ubufox software-center unity-2d* unity-asset-pool linux-generic unity-common unity-lens-* unity-scope-* unity-services indicator-messages indicator-status-provider-mc5 indicator-appmenu appmenu-* unity-greeter overlay-scrollbar liboverlay-scrollbar* zeitgeist zeitgeist-core zeitgeist-datahub activity-log-* libunity-misc4 libunity-core-5* globalmenu* update-manager update-manager-core gir1.2-unity-5.0 usb-creator-gtk ubuntu-wallpapers* ubuntuone-* ubuntu-mono light-themes adium-theme-ubuntu ubuntu-sounds nautilus nautilus-sendto-empathy

apt-get --yes autoremove
#apt-get --yes purge `deborphan`
#apt-get --yes purge `deborphan`
#apt-get --yes purge `deborphan`
#apt-get --yes purge `deborphan`
apt-get --yes purge deborphan gnome-screensaver
apt-get clean && apt-get autoclean

rm /etc/network/interfaces
touch /etc/network/interfaces

echo "# interfaces(5) file used by ifup(8) and ifdown(8)" >> /etc/network/interfaces
echo "auto lo" >> /etc/network/interfaces
echo "iface lo inet loopback" >> /etc/network/interfaces

echo "Don't forget to purge the LightDM after reboot."

END OF SCRIPT

Step 6: Reboot, and purge the LightDM with "sudo apt-get purge lightdm"

Step 7: *OPTIONAL* LibreOffice isn't fully installed, you can fix this by using "sudo apt-get install libreoffice" This will also install OpenJDK. if you want the oracle
version of java, use "sudo add-apt-repository ppa:webupd8team/java" "sudo apt-get update" "sudo apt-get install oracle-java7-installer" before you fully install libreoffice.

Step 8: *OPTIONAL* You can install the codec with "sudo apt-get install mint-meta-codecs".

You're done, congratulations!

*NOTE* You might have the start up the Mint Update program manually for the first time. To show the plymouth theme, configure your /etc/default/grub like this (don't forget the "update-grub" command after editing):
 

START OF SCRIPT

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0
GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=0
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash profile"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"

END OF SCRIPT

P.S. I'm not a native english speaker, please excuse me for eventual bad grammer.