Two weekends and a snapped bleeder screw on my 2004 Focus rear caliper

I went in to do a simple rear pad swap on my 2004 Focus two Saturdays ago and it turned into a 14 hour job spread over two weekends. The caliper piston would not compress back in, not with the tool, not with the C clamp, nothing. So I figure the caliper is frozen and I start pulling it off and the bleeder screw snaps flush with the caliper body. I tried an extractor bit, then heat, then drilling, and just made a bigger mess in my driveway. Ended up buying a rebuilt caliper for $78 and a new set of pads, and honestly I should have just done that on hour two instead of hour nine. The whole time I kept telling myself I could save the original part, and that stubbornness cost me a full weekend of football. Any of you got a trick for a stuck rear piston on these things or do you just swap the caliper the second it fights back?