removing old heatshrink

[wez]

i'm fixing up an old marshall valvestate (the first model) for a friend, and the 12AX7 has been covered in heatshrink, right down to the PCB (ie covering the socket completely). it won't pull out, and 20+ years of heat etc has essentially vulcanised the shrink, turning it into a tough shell which i just can't cut through or remove.

i'd rather not have to completely desolder the socket itself... any suggestions for removing the heatshrink - solvents etc?

[Alistair]

I've had a few things where the old heatshrink is tough as leather, but I find once you can get the first cut the whole way through with a scalpel, it's pretty easy to follow that cut and slice it open.
Otherwise I'd try heating it a little bit to see if it softens it a touch- sometimes it seems a little softer when hot and only rock hard when cool.

Good luck!