B/U light socket replacement

Yes, you have to remove the bumper. Open the trunk and you will see three bolts on each side. Have a friend hold the bumper while you take the bolts out. Be sure to unplug the two electrical connectors and push the grommets through before unbolting the bumper.
Slide the bumper off as a unit and set on a bench. Use a moving blanket to set it on for padding. There are two screws per side to remove the light housings. I think they are 3/8 socket head. The original sockets are crimped on the housings and are not made to be replaced. You will have to do some searching for some that will snap in the hole after the originals are removed.