I don't know the first thing about tablets or mint, so I'm just skimming the link you provided. You should have the xserver-xorg-input-wacom in the mint repositories (it's in ubuntu, and mint is derived from ubuntu so this seems pretty likely.)

sudo apt-get install xserver-xorg-input-wacom

You can log out/in to restart the x server.

Modern distros don't usually use the X.conf files anymore, so you're going to have more luck with these directions: http://sourceforge.net/apps/mediawiki/linuxwacom/index.php?title=Xorg.conf.d

You'll probably need to make the directory they're referencing:

sudo mkdir /etc/X11/xorg.conf.d

When it comes time to edit files in that directory, you're going to have permission problems...use gedit to edit with:

gksudo gedit /path/and/name/of/file

Not a lot of detail, but I hope it's enough to get you moving :)