there's no special trick to it afaik, but i wouldn't know for sure.
Determine what is jamming the piston and get that out of the way. If you broke a ring, some part of the rest of the ring is probably expanded into a port. If the ring is caught in the exhaust port it should be possible to reach into that port and push the ring back into the ring groove..
I guess if you can't get the piston out a last resort would be to save the cylinder and connecting rod, etc by cutting the piston out.
Call or have a shop look at it before you just take a hammer to it.
Rings break when they get caught in a port. One reason they may get caught in a port is insufficient ring-end clearance.. and I suppose heat build up due to a poor run-in could do it. There may be other reasons.
Do what you can to save the cylinder and rod .. get a few expert opinions from engine repair shops.