Caliper pistons stuck

[TSpencer]

So planned to rebuild the front caliper on my '86 350X, but when I tried to remove the seized phenolic pistons, the tops just crumbled off leaving the pistons stuck down in the bore. I tried compressed air with no luck. I then got frustrated and went at it with a and cold chisel thinking I could break up the phenolic material. Well, I got a little of it broken up (that stuff if fu@#ing hard!) but managed to put a bit of a gouge in the bore. Hoping I can get the rest of the pistons out, blast and polish the bore and hope for the best. 86 front calipers are hard to find without spending $$$. So a couple questions.
1. Any ideas how to get the remnants of the phenolic pistons out without further damaging the bore? I was thinking a media blaster may do the trick and just blast it away? (excellent excuse to purchase a bench top blaster BTW)
2. If the bore is shot, can I swap to an 85 caliper? If so do I just need the 85 caliper and bracket or are other modifications needed? Thanks!

[Aulbaugh]

Yes an 85 caliper will work. For a stuck piston I pull the pads out and put a c clamp on a piston and pump the brake lever to push the other piston out.

[shortline10]

Another trick is to use a grease gun were the banjo bolt screws in , very effective on seized calipers .

[big specht]

I second that you will be amazed with the power of hydraulics

[TSpencer]

Thanks guys- Grease gun worked to an extent but they're out. Cleaned the bores out good and the gouge didn't look so bad. I put the new seals and pistons in and I'll see what happens. Worst case scenario is it leaks and I'm back to square one.