Taken from the Tech Repository:
http://www.thetechrepository.com/showthread.php?t=23
Credit goes to FreeCableGuy.
Picture directions and full thread can be found here:Removing the Intel IHS has always been a great way to drop temperatures as much as ~10-12C sometimes providing additional overclocking headroom; sometimes permitting the lower voltages for identical CPU core speeds...
The problem with removing the Intel IHS is that the newly exposed core sits lower than the edges of the LGA775 bracket cover piece making it impossible to make the much needed CPU <-> heatsink/waterblock/evaporator head contact without completing time consuming, permanently altering modifications to your cooling solution. Not any more!
***Note: Be sure to protect your pins when doing this! A slip of your hands could quickly ruin your expensive motherboard!
Open the LGA775 socket on the motherboard that you will be "modding." Then, using a slight twisting force, push in on one side of the bracket while pulling out slighting on the other side. You should find that the hinge on one side easily moves past the retaining slip which allows you to completely remove the cover. You easily later reverse this modification by re-installing the cover just as you removed it.
http://www.thetechrepository.com/showthread.php?t=23
Credit goes to FreeCableGuy.