Ok. I've removed/installed alot of heatsinks (mostly on AMDs), but for some reason this one is giving me trouble. I must admit it's embarassing.

It's the stock HSF that comes with PIII 1.0Ghz retail CPUs.
It has plastic clips. Pic:

What's the secret to removing these? It tried pressing down on the green clip, but all I have to show for it is a sore thumb. The mobo was even bending so I was afraid to try much harder. Does this clip slide sideways or something? Most AMDs have a spot to insert a screwdriver and pull out.. works like a charm. But these clips are plastic.

Any hints would be appreciated. I only had about 15 minutes to play with it, and I didn't accomplish a single thing except the need for a banaid.