Come ON. I'm 69 and have lots of arthritic-like issues. It is not all that much work to remove the seat. Throw together some extensions and a 1/2" socket and tape them all together. Put down a mat, cardboard, "whatever." Lay down, stretch out, and reach back with the "tool" and unscrew the bolts.
This is as opposed to "drilling out the lock" which has a HIGH likelyhood of breaking a bit/ slipping off with the drill/ and then.......dicking up the trunk lid.