740: rear shock upper mount issue

Replacing rear shocks in '86 740 turbo.

Upper and lower bolts came out easily with air,and I freed the lower shock mount on both sides.

The problem is with the upper shock mount: both are stuck and will not free up to allow removal.

I assume the side walls were compressed too hard during prior installation, not allowing room for the shock to free itself.

Any suggestions?

I assume I need to spread out the side metal somehow to permit clearance, but I can't figure out how to do it.

If I remove the rear seat will I have access from inside the car to the upper shock mount, and if so what is the best way to attack the problem?

Got it out, but now can't get the top one to go in.

Been using a grinder to take metal off the edge but this makes me nervous; I see no other way to do it.

Is there one?

lube?

Nah, they're in now.

I just ground down the sheath that covers the bolts til they just fit.

Tedious: grind, check, grind, check...

I gotta think this is a common problem caused by too thin of steel used: poor design.