You can find the repair manuals here. I recommend following the logic board guide, because it will walk you through taking everything out of the laptop and then you can clean the parts.
Also, what do you mean by your MacBook is running slow? Is it slow to load programs or slow to boot up?
Your MacBook may benefit by upgrading the RAM with two 1GB RAM chips.
I recommend upgrading to Snow Leopard if you haven't already. Also, check out this answer to speeding up your MacBook.
RAM Upgrade / 1 GB / PC2-5300 / Low Profile / 200 pin, 667 MHz — 26 available at 14.95 each.