Need help with rear bumper

The bumper bolts may just have to be ground off if you can't get to them from the back.
Tape the bumper up real good around the bolts and grind the head off.

Are you asking about the screws that hold the tail light assy to the bumper that you have to go down between the rear panel and the bumper to get at?
Mine come off with the bumper, not sure about yours.

Edit, nevermind
Your tail light are in the rear panel instead of the bumper, so I don't have an answer for the screws you asked about.
Sorry.