Are you able to use the manual crank? If not, you yank the transmission line and turn it with a modified 1/4" drive, but you would have to do each side separately. This will skew the seat from left to right and will make it difficult to re-establish true forward direction later, but will be good enough to clear the bolts so you can undo those and do your work on a bench rather than in the car.

Good luck

 

Don't forget to disconnect the battery.

 

And if you disconnect the battery BEFORE you raise the back of the seat up all the way, it will be difficult to get an allen wrench in there, there's not a lot of room.