I've never opened the actual drive. I'd just try plugging it in and supplying power, and then gently shake it a bit from side to side. It's not really a scientific process, but just something i've had work before. I have heard of people opening drives up and manually helping the motor start (maybe on this bbs), but by that point you really should have decided that your only other option is throwing the drive in the trash. If you do go that route, make sure you've got it on a non-essential IDE connector, as who knows what it might fry.

Matthew