I replaced mine last summer without too much hassle. Remove your grab handles and pull back the headliner just enough to get a tool in there and then remove the sensor. It just unplugs and then you can plug in the new one. Just be patient. The screws for the grab handles are hidden and can be accessed by lifting up the plastic covers at the sides of the handles. They just need a little prying up. They do not come off so just pry up and it lifts up to access the screw. The sensor is just a 'clip on' and can be removed pretty easily.
When I did mine I removed the plastic molding that goes along the inside of the windshield and along the top inside of the door. You just need to be careful because it is plastic and plastic clips. Give your self about an hour for the first attempt at it.
Good Luck
Marty