I used to have an '02 grand cherokee limited and I put a hitch on it. I actually ordered the OEM part from MOPAR for mine, because I wanted it to look professional. It's actually really simple to put it on--you just have to take the bumper off and cut out a slot for the receiver.
If you want to go with an easier route, go to your local farm store and get a reese hitch. It will come with instructions on how to put it on--they are very simple!! Most require no drilling. If you can tighten a bolt, you're set!
Good luck!
-Shonn