Replacing upholstery on my 83 SL. How do I remove the two large screws on seat back?

[bcolins]

First off, if anyone can direct me to a tutorial on this, that would be great. I did find a brief and generic one on Diesel Giant,....but need something more specific to the 107 cars.

My current road block is the two large countersunk phillips flat head screws holding the hinge plate hardware on to the seat backs. I first tried a large phillips bit with my 3 foot breaker bar when a regular phillips screw driver would not budge it,....then went to a hammer-driver with phillips bit........wacked it several times while twisting and still nothing,......next got out my impact wrench, hooked up the air and let it rip,.........nothing.

Any suggestions for getting them out?

I noticed when removing the single large allen head bolt that held the hinge plate to the seat bottom, that they had blue thread lock on them. I used my 3 foot breaker bar with an allen bit to get those out,......and those suckers were reluctant to come out,.....probably never would have gottne them out if they were the same phillips screw used on the seat backs.

Brian in Austin