Re the GlobalWin FOP32, it is not an easy HSF to mount. The tension on the retaining clip is one problem, the other is that the heatsink is pretty massive. Here is how I did it and hopefully will make it simpler for others.
First, take some of the tension off of the retaining clip/strap. Easy to pop the fan off, then pull the retaining clip out. Take a two pliers and gently take some of the bend out, thus reducing the tension. Then reattach the fan (or you could leave off until you have mounted the HS, very simple to reattach).
Second, with my mobo already mounted(Abit KT7 Raid), I found it easier to remove the power supply to get it out of the way. You can really use the room. It is only 4 screws. I didn't have to disconnect any power connectors from drives, etc. Just pulled it up and layed it on top of the upper drive cage. You now have excellent access to the socket.
Third, scrape off the junky thermal tape which comes on the HSF and put some fresh thermal compound on the CPU.
Fourth, hook the back side of the retaining clip onto the socket latch (the one away from the power supply) then you are ready for the front side (the one with the little pivot).
Fifth, take two small blade screwdrivers (or something similar). Depress the end of the retaining clip with one screwdriver while guiding the pivoting hook with the other screwdriver down and over the latch.
Sixth, replace the power supply.
It takes longer to talk about it than do it. Your reward after this is all completed is a relatively inexpensive heavy duty cooling solution that will allow you to abuse your Tbird/Duron without fear.
Mac