Wedge said:
Ok, so the answer is "yes" clean that off.
Use either: non-alcoholic baby wipe, or Tempo or Cleanex?
You will get a much better seating between heatsink and processor next time Wedge by cleaning it all off before applying the new compound. Besides, the old and new compound won't be completely compatible.
Personally I have used 99% isopropal alcohol and a few cotton swabs heaps of times without problems. It safely cuts the compound cleanly and evaporates without leaving a residue. Do NOT use Rubbing alcohol though, as it has a lubricant added.
Cleanex is too flimsy and makes too much lint. Tempo.... a paper towel???
Baby wipes are O.K. but beware..... in the U.S. most baby wipes have additives like lanolin or aloe vera which are lubricants. Many also have perfumes which are oily. A plain glycol based wipe (usu. labeled for sensitive skin) will do.
As for putting it all back on.... the AMD.com vid that ChiMusic mentioned is a perfect tut to review a few times before doing it yourself.
In the end, it's really easy to do. Just be patient and remember not to overdo the compound and you will be fine.