Stripped Northbridge fan screw

[Slavegamer]

I noticed my fan had seized up so I tried to take it off for replacement. I stripped the right side screw , completely rounded it out . The left screw came out with no problem . So that idea came to a halt. Now because it has a shroud over the fan, and only blows air out the left side, it is hard to clean with air so I did what I could then put some wd40 on the fan motor , got it working again. But each time I start my pc I have to shoot the fan with compressed air to get it going , then it runs ok.
I found a aluminum 60mm fan that will fit I just dont know how to go about getting that screw off.

I though maybe to take out the mobo and take off the heatsink and just drill the screw head off. Or do that with the heat sink attached and just mask off the mobo with tape. Dont want metal shards all over the place , is drilling a bad idea ?
yah Its on the heatsink but do I risk electrostatic damage? I would like some opinion.

last few days I noticed the fan rpm going up to 5000 then back to 1500 in 15 to 30 second intervals
and I am only using browser. Getting loud so I know its going to crap out any day now . Thanks for reading and any thoughts you might have -cheers

fan with x58 logo

 

[Slavegamer]

Thanks for that, I saw a post where a guy with my mobo had his nb fan die and could not get it replaced. He took a pic of the alloy fan on his nb grill to show it fit perfect, also looked better with the fancy led's .