Hello,  my friend has just gotten a new fan/heatsink for his P4 processor  (Socket LGA 775)   and i offered to install it for him,   i have done this before and am familliar with the process,  but i have not "replaced" an already existing fan/heatsink   so i wasn't sure what to do about the leftover heatspreading substance on the processor.  should i carefully clean it,  and with what, or should i just put the other one on there,   notting that the new one has it's own fresh layer of the stuff.  
thanks for your HELP.

DoomsayerUse a razorblade or other fine edged instrument to carefully remove most of the old thermal pad/compound. Then, soak a paper towl or cloth with some rubbing alcohol and carefully wipe the REMAINING compound off.hey,  thanks for the quick reply,  just one more thing,   should i remove the processor or just LEAVE it in the mobo?I believe the best procedure is to remove the processor for cleaning.  Be carefull not to bend the pins on it.  Here's one reference on Replace a CPU's Heatsink and Fan which advises removing the processor.thanks a lot for your help soybean,  i greatly appreciate it.  

DOOMSAYER