If you do some searching you'll find that heating up bakelite can be very dangerous so heed those warnings as best you can! I found on mine it was no problem at all to just chip away at it. If I found it was in a hard to reach area I'd do my best to replace the conduit altogether if possible just to avoid messing with it but i've only found it inside the junctions, switch or socket areas on mine.

Set of different flat blade screwdrivers and a small hammer to just chisel away and dump.

I've done a Bennett 966 and Tokheim 39 short and on both this method worked well.