How the heck can I release these piston rings (rock-solid, they are :-/ ), and also the cable adjuster has snapped off almost flush to the adjuster block (bottom left of pic)......is my only option there to drill & re-tap?

How best to release these ?
My advice is to just break the rings. Those rings have served well and need to be replaced.
Can't get into the ones on the left hand piston as they're solid & there's no way in.
I think I'll submerge them for a few days in diesel & hope that breaks the bond.
I think I'll submerge them for a few days in diesel & hope that breaks the bond.
Try breaking the rings by inserting something or using a chisel carefully at the point where the end of the rings join
