Removing 9800 Pro shim?

[GPU Fanboy]

Alright, so I got an arctic cooling VGA silencer rev. 3 (http://www.svc.com/vga-rev3.html) for my 9800 pro, and upon removing the the HSF, saw that my core was an R350 :( . The new cooler helped my max OC go from about 415 Mhz core to 430. However, I would like to do better, especially since most people can hit 440 or so without a volt mod. Those who have had a 9800 Pro before will understand when I say there is a square metal shim surrounding the core, and the height of the core is lower than the surrounding shim. Thus, the stock cooler has a square bump in the middle so that it actually touches the core. However, the new cooler does not touch the core. Does anyone here know how to remove the metal shim, so that the new HSF can touch the core? I think that could be holding back my overclock.
Thanks in advance. :)

[Fronic]

I have 9700np and the shim came off after sliding a very thin metal knife under it. Pry one side off then carefully remove the rest of it. When you tighten the heatsink MAKE SURE you do this slowly and gently, tighten one side, then the other little by little.