The seat had an armrest/storage box, with a broken lid. After I ripped off the lid, there was still a giant hinge plate sticking up, attached by screws I couldn't reach. I ripped it apart for awhile with a crowbar and pliers until I could see far enough into the structure to realize all I needed was a torx bit to unbolt the whole armrest. What I've learned about this truck is anything I'm trying to remove or replace is probably bolted with a T50.