Akunthita put so much work into this, I feel compelled to post...
I'm certain by now that folks have heard that LEGO will be gluing minifigs to bases for all future magnet sets. Heads, accessories, and technically arms can still be removed, but the legs are glued to the base and the torso is glued to the legs (and the ankle bone's connected to the leg bone...).
There have been a variety of methods explored to safely 'liberate' the figs from their bondage. Akunthita has literally explored them all, but has found the most success with a hot water bath technique. I'll leave it at that, and highly recommend you visit Akunthita's site TheBrickBlogger.com.
I'm considering this a tutorial, so you should read our customization tutorial disclaimer before performing any of the recommendations provided within.
