Just popping it off the figure.
Okay. First, you'll have to run a hot bath. You'll need a litre of neat vodka, a towel, some WD40, a screwdriver, a lighter, a rubbing cloth, 2oz of butter and a small knife.
Take the head, pull gently till it pops off, then put all the other stuff away. Unless you fancy a bath and a glass of vodka.