Keep or replace preapplied thermal compound heatsink laptop?

[skypup03]

I'm going to replace the fan heatsink assembly with one from a gateway-authorized part dealer. The part has what appears to be preapplied thermal tape or compound where the part makes contact with the top surface of the cpu. Given that this laptop is about 4 years old, I'm not sure if it's worth trusting the the pre-applied compound for the cpu and the already loaded thermal pad for the gpu on the new part.

Should I remove the pre-applied thermal compound? The thermal pad? Both? If replace, I would be planning on using Arctic Silver 5. Should I just leave the thermal compound that's pre-applied and also spread a thin layer of arctic silver 5 on the cpu? Remove the pre-applied stuff and just use the Arctic Silver 5? Help! I'm so unsure what to do. Thanks!

 

[WR2]

Should I just leave the thermal compound that's pre-applied and also spread a thin layer of arctic silver 5 on the cpu?

The easy part of your question to answer - don't do this.