I installed mine last weekend. Here are the bonehead things I did to make it a two hour job instead of five minutes:
1. Assumed the ball stud would be above (higher than) the tailgate hinge. When it wasn't there, I thought maybe it was behind the driver side tail light.
2. Removed the driver side tail light. Also not there (duh).
3. Installed driver side tail light. Broke plastic clip.*
4. Went to Autozone to get new plastic clip. Got one that was kind of close. Had to trim to fit.
5. Discovered ball stud was lower than tailgate hinge, down in a sheetmetal tunnel on passenger side.
6. Tried unsuccessfully to reach down and clip the damper onto the stud for quite some time. Items were thrown.
7. Realized that the lower stud was easily reachable from under the pickup.
8. Completed job in five minutes.
Not my finest hour, but maybe it'll help someone else save a little time and frustration.
*The correct plastic clips aren't sold separately; they come with the tail light assembly.