[Jelly]

demillso already gave some good advice. The trick is adding heat.

I should have remembered this from my work with plastics, but I tried over and over with the coffee thing and it never worked. Then I added heat (I used a regular oven at about 150 celsius for maybe only ten minutes) and it worked - it really worked.

Scuff it with fine sandpaper or steel wool, put it in a shallow pan with enough coffee to cover it, then heat it and check the results. GO SLOW. You have to be careful not to get it too hot because the plastic will shrink. Mine shrank enough to make it difficult to get the pickups back in, but I got it worked out.