removing hsf on aiw 9000

[x98gulinski]

The fan on my hsf is about dead, or about to be dead, I want to remove the hsf, but it seems to be glued on, What is the best way to remove it without damagin gthe core? I've heard of the freezer trick, would that work, or would it be better to try and twist it off after it's been running for a long time and it hot to the touch?