How to replace rear keyless antenna, 2008 CX-9 GT w/Trailer hitch?

Hi All - I need to replace my rear keyless antenna and I am wondering if I need to remove the hitch? When I got under the car, the antenna was essentially hanging there. It was not held in which screws (both holes on the antenna had broken off). I cant seem to locate where it would be secured to the bumper. Does the Trailer hitch need to be removed? Any help would be greatly appreciated.

Thank you!

When I get home, I will take a few photos.
The keyless antenna mounts in 2 different places, depending on if the hitch is installed or not will determine the location for where it mounts.
Again, later today I can take some photos.

If hitch mounted you use bolts. Mounts to hitch. If no hitch, mounts to rear body directly behind spare tire using nuts. There are 2 threaded studs pointing away from the spare tire, pointing toward the rear of the vehicle. So you need the 2 nuts to secure the sensor to those threaded studs. However with the hitch, the nuts are welded to the hitch, so you need 2 bolts.

Photobucket just hijacked all its users so now I need to find an alternative site to share photos.

If you send me a private message with your email, I will email you a few photos that show exactly where these mounting locations are.

Thanks