Anyone know of an easy way to separate these without doing damage to the card or the two parts of the central plastic peg once they have already been built?

Is there a knack to it cos mine seem jammed in pretty darn tight? Apologies if there is already a post on this but a rudimentary search on this forum pulled up nothing.

I used my fingernails to lever up the Male end of the peg slightly. Then I pushed the dial halves to the extremeities and pull the dial apart using the cardboard. I made sure to avoid putting pressure around the cut to reduce any bending. A little bit of pulling and twisting and they come off. I did this for about twenty dials in order to paint the cardboard edging.

Use a flat-head screwdriver. The thinner the better, but wide as to not pierce the cardboard.

Insert, then pry up gently going around the entire dial until both plastic pieces give way.

Maybe once you have a decent distance between the plastic pieces use some pliers to help twist it off, being careful not to crush the plastic.

It's a press fit so it will take simple pressure to pull it apart. You should be able to get your fingernails or a thin metal sheet and just work it up evenly around the circumference and it will pull apart.

A pocketknife blade works pretty well. Just work it under the center peg and work it a bit at a time until it loosens up.