Hi,
it appears that one out of the 5 bolts to remove to heat sink seems to be a 3.5mm hex screw rather than 3.0mm. It's the one that is located on the left side if you look on top of the sink:
Strange but the 3.0mm hex driver simply does not fit and a 4.0mm is too big.
I had to reassemble my MacPro without being able to replace my CPU...
Peter
Peter,
The bolts should all be the same. If you are unable to lock the hex driver into the bolt, then that one might be stripped. A mishap at the factory, perhaps?
Just keep trying. I don't know what to do if it is stripped, but let's hope that it is not.
The 3.5 might be able to get a grip on it. Do you have 3.5mm hex driver?