I changed out mine.
First thing you have to do is remove the back seat and pop off the plastic covers that go over the seat belt retractor.
This is the hardest part of the entire install. Even if you going to pay someone to do it, you will save alot of money doing this step yourself. I saved $200.00 in labor charges.
Then remove the OEM window and clean out as much of the old caulking as you can.
Once the caulk is out you have to apply a coat of special adhesive primer. (about $25.00)
(Do not skip this step)
Once the primer is on and dry, apply the caulking. A power caulking gun is nice to have.
Then the window is pressed into place, and the metal tabs on the inside are bent up to hold it in place and keep the pressure on.
Last step is to let it dry for 48 hours.