For this you will need a adjustable wrench to remove the bolts on the heat sinks.
Just follow this guide and read every step and you should have your Xbox up and running in about 20 minutes
STEP-1) Turn the motherboard over this will be your work area. What you are going to do first is remove the two large x-clamps from the motherboard and replace with bolts that have been custom made for a precision fit on the Xbox 360.
STEP-2) Removing the x-clamps is pretty easy using long needle nose pliers or a screwdriver. Don't use a torx 10 o torx 8 screwdriver as you will strip the end. After all four corners have been loosened simply remove. Be careful not to touch the motherboard as you can damage the traces.
STEP-3) Now remove the GPU and CPU heat sinks from the motherboard . You will see the GPU and the CPU exposed and will probably be quite dirty with old thermal grease.
STEP-4) Now remove the bolts from each heat sink. They can be quite stiff so use a solid set of pliers or mole grips.
STEP-5) Now to do some clean up. The old thermal grease on the heat sinks AND on both the CPU and GPU needs to be thoroughly cleaned. Use the rubbing alcohol for the GPU and CPU. Its pretty hard and baked on so it takes a little effort to do a good job. This is VERY important.
STEP-6)
