Chosen Solution

…..i have to do thermal paste and have ruined a screw head badly on thermal sink. I have tried all the solution available online but no luck.Could anyone please help me here.

You need a screw extractor set. They are not very expensive. Make a starter hole with a small drill bit. Then place the extractor tip in the starter hole you drilled. Slowly turn the extractor counterclockwise and press down until you feel the extractor threads bite into the screw head. Turn the extractor slowly to back the screw out enough to grip it with the locking pliers and finish removing . If you are not used to this sort of work “slowly” is the key word here. Don’t rush the job and rest frequently. Watch a few videos on the web if unsure of what you are doing..

You need a little saw or something like it to make another line in the screw

I don’t know if you already tried the elastic trick but if you haven’t then watch this video https://www.youtube.com/watch?v=IqIDjb1c