There are lots of guides on how to lap (sand) your CPU and heatsink online. I've taken information from some guides and modified some things to what I did and posted it here in case someone wanted to give it a try. Thanks to Ski and Magicman for their advice.
Disclaimer: This WILL void the living hell out of your processor's warranty, you can't deny that you lapped your IHS like you would deny that you overclocked it if something went wrong - I am NOT responsible for any damage that may occur your CPU in this process (not much damage can really be done by lapping your IHS, except for bending the fragile gold pins - just be careful, and read the steps carefully)
First off, IHS = Integrated Heat Spreader - its the silver 'thing' mounted on top of your Pentium 4's, and Athlon64's (excluding mobiles) - its actually a piece of zinc-plated copper bonded to the Core and/or PCB if your processor to protect it from being crushed during Heatsink/water block mounting
So you say, Why lapping?
Lapping or sanding the CPU can greatly decrease heat when overclocking.
Lapping is relatively safe and inexpensive
It doesn't cost much to do and it reduces heat from the CPU. Do I need to say more?
BEFORE
AFTER
1. A Intel CPU socket 478 or LGA775 (socket T), or AMD CPU socket 754 (with IHS), socket 939, or socket 940 - this can only be done safely to CPU's with an IHS
2. I used 220, 400, 600, 800, 1500 and 2000 3M WetorDry/waterproof sandpaper. You can go higher but I think going up to the 2000 did an excellent job and hey I did enough sanding for one day. You can pick up your sandpaper at local hardware store (Crappy Tire/NAPA) and there are some online stores have pre-built lapping kits.
3. A neoprene foam piece large enough to cover the surface area of the gold pins on the back of the CPU, or a piece of foam that came with the CPU. For my E6600 I used the protective piece that came with it and some scotch tape to ensure that it stayed on during sanding.
4. Preferably a piece of glass or Plexiglas (which I used) at least 5 inches by 6 inches wide or a really flat surface.
5. Any good tape, scotch, masking, painters, duct, .......
6. A felt tip permanent marker.
Ok that’s it, not too many materials needed; here is what you do for your CPU.
1. Take the Neoprene foam or CPU protective foam, and gently place it on the back side of the CPU's gold pins, make sure that it covers the pins decently (be VERY careful not to bend the pins - especially A64 pins) or protect the pins as I did with my E6600 with the plastic piece that came with it.
2. Take a piece of the 220 grit sandpaper and place it on the flat glass surface, and tape the top of the sandpaper to the piece of glass/Plexiglas. (Take some water and wet underneath the sandpaper to help it stay in place and press it down to give you a flat surface to work with.)
3. Take your permanent marker and mark an X from corner to corner on the IHS of the CPU.
4. Now take the CPU and gently move it in a circular motion on the sandpaper, rotating 90º after every 15-20 seconds of lapping to ensure you are lapping it evenly (you can be sure it's lapping evenly by the X you made with the sharpie), when the X is completely sanded off w/ 220 grit and the copper is exposed completely, you are ready to move on to the next step/grit paper
"How do I know how much I should lap this sucker before I ruin my CPU?
Use the 220 grit sand paper until the entire IHS surface is copper, then stop and get ready to switch to a finer sandpaper.
I sanded for quite a while and I am tired of little circles.
5. Once you reach the copper (and sharpie'd X is gone) on the CPU take off the 220 grit sandpaper and switch it to the 400 grit, tape it down, and start going in circles again. - follow step #4 lapping procedure (rotating object being lapped 90º after every 15-20 seconds of sanding/lapping)
6. Repeat step 5 with 600, 800, and 1000 grit sandpaper.
if you continuously look at the surface of the CPU you will notice that the deeper looking scratches go away rather quickly and after a few minutes it will start to look smooooth...oh yah that’s what we want. You will feel the CPU glide along the sandpaper as it gets smoother.
7. Now if you went the extra method, getting the 20000 or 2500 grit sandpaper, (this isn't necessary, but will still help... it's just a perfectionist thing), then you will follow up with this last switch out of the sandpaper to the 2000/2500 and move the CPU in circles again until you have a semi mirror finish. I would have used the brasso if I had of remembered to pick some up.
8. Now clean up your mess, make a double check to make sure that there is not metallic dust on the gold pins from the sanding. (I used some compressed air).
9. Clean the CPU with cotton swabs and high-purity isopropyl alcohol nicely (let it dry for a few minutes - if you got some alcohol in the s478 P4's IHS hole, let it dry for 30 minutes to be sure that there is no alcohol left under the IHS).
Some Completed Pics
10. Apply thermal compound (Arctic Silver 5 recommended), insert CPU into socket, and overclock that sucker.
Now on to the Heatsink. The heatsink is an Artic Cooling Freezer 7 Pro for anyone looking for a good cooling and affordable heatsink.
The heatsink presented a problem. I could not lay it flat to lap because of the mounting bracket and sanding by free hand would be uneven I would never get a perfectly flat base (which would be a bad thing). So this is what I did. I cut a piece of melamine board and Plexiglas to a width that would go between the mounting posts on the heatsink and easily cover the copper block. I taped them together so that they would not move and taped them to the sheet of Plexiglas that I used for lapping my CPU to ensure that I had a stable flat surface and then placed these flat on my computer desk. This let me tape the sandpaper to the flat Plexiglas and it was raised up enough that when it was laying flat on my desk I could easily move the heatsink back and forth without touching the attached mounting posts . The lapping was the same as the CPU but I went back and forth roatating 90 degrees every 10-15 seconds, working my way up to the 2000 grit sandpaper and a mirror like finish.
i wanna try this