How to remove 13 year old metal loaded thermal paste [duplicate]

Possible Duplicate:
What chemical should I use for removing thermal paste?

I've got an AMD-K6 CPU which has a duff fan, the thermal paste has gone solid and won't come off with alcohol or akasa heatsink cleaner (smells of citrus, like label remover). I'm assuming the residue contains copper as it polishes up nice and shiny but turns green when exposed to liquid. I've experimented, using a blade and crocus paper on the underside of the heatsink which worked quite well but I don't want to remove the CPU or subject it to the same rough handling (no spares).

Does anyone have a handy tip for removing this stuff from my CPU in-situ?

I'm surprised this has been closed as an "exact" duplicate as it refers to a metal residue that has been left behind after normal cleaning using TIM remover.

Heating the paste by turning the processor on may soften it enough to be manipulated (carefully).

If not, see the procedure described here :
How to Remove the TIM from a Stock AMD Heatsink and CPU.

Specialized products are also a possibility, such as ArctiClean Thermal Compound Cleaner
(have never used it and cannot vouch for it).
Ask at your local computer store, or search "thermal compound cleaner" on your favorite Internet shop.