If that's a question for me, Matt, I went into a bicycle shop and asked for a crank pulling tool and a bottom bracket extraction tool.
The crank puller has an external thread which matches an internal thread on each crank arm. It also has an internal thread which carries a matching hreaded slug. You screw the tool into the crank arm, then wind in the slug. The slug presses on the outer face of the crankshaft and pushes the arm off its taper.
Yes, it was & thanks for the reply.
I think I'll leave it to LBS given my limited mechanical abilities.
Best
Matt