I found the following info on newsgroups:
"I just took vise
grips and grabbed the sides of the heatsinks and gave gentle twisting
as I pulled, and they popped right off. You've then got to clean off
the glue on the chips with a knife or some such instrument - the most
delicate part of the operation, especially with capacitors sticking up
around the chips."
"
used a butter knife myself, Note that the edge of the
VSA100 chips have no support underneath and thus are
extremely easy to break.
I used the wife's fingernail polish to remove the residue glue. It
worked very well. I bought 2 Radio shack socket
seven heatsink/fans and used the original fans on the new
heatsinks. Be aware that the top of the VSA100 chip is
very concave in shape and requires alittle more than
usual heatsink compound.
To attach the new Heatsink/fans I used just a drop of
superglue in each corner. There was a website here in
the past which had a very nice procedure for this, maybe
someone else would post the URL for you."