lol me and my friend just went at it and like striped the "screw", I'm not sure if it was a locking pin or not, since there were 2 other screws on there (total of 4) that came off fine, anyways, I had a cordless drill and a very tiny bit, needless to say, I drilled the 2 screws to the point where they broke off >_< very carefully, end result, we managed to get the zalman fan in and its working great =D
A little brute but, it worked xD