unfortunately there's not a way to replace the touchpad easily if u don't want to pay for it... u should just buy a usb mouse

I think the usb mouse is the way to go alo ... I picked up a really small optical usb mouse w/ retractable cable for about 15.00 us on sale .. it can run you 15-30 dollars.

If you really have your heart set on taking the laptop apart .. download a takeapart manual or service manual, have the right tools, plenty of time and patience and a good work area, have a digital camera to log your work for reassembly and a little recorder to take audio notes... your hand will be busy enough... make sure you make a screw matrix and have some pill bottles or zip locks for the small parts.. and take pictures of them... I know this seems like overkill but I developed good habits from working on firearms and explosive devices and I hate ruining precious equipment if ai can avoid it.

I stil oke the mouse or tackball option

I was thinking ... Can you find an ultra thin black plastic sticky pece or vinyl. I know this is a stretch .. but I've used plastic sheets on touch screens and ipod controls .. Maybe if you make a template .. you can cut some wide thin black colored tape to fit tightly within the touchpad opening...