You can try here:
http://repair4laptop.org/notebook.html

or google for disassembly intstructions
for your make and model.

A word of warning:
- Don't touch any cables or wireing with bare
hands. (they don't like oil from hands)

- ground yourself
- make a written diagram and drawing of where
each screw goes and write down the order you
started with
- remove all power sources (plug/battery)
- remove all auxiliary accessories and ram
- use scotch tape for all small parts and screws
so they don't get lost.

And if you're luckly you'll *ONLY* end up with
one or two extra screws at the end of your project.

Goodluck