This is what they look like after you get the battery open. Usually, you can remove the security screws with a bit of work. However, I wasn't able to. My security bits were too short to reach into the tiny opening for them so I resorted to brute force and used a hacksaw. Be very careful not to cut too far and damage the batteries!
Once it's open, you can see the BMS board and the leads on the copper colored flexible cabling. The battery is insulated from the sides of the housing by a thin sticky paper tape. You can see the spring for the locking tab sitting on top.
This is the case popped open on one side after cutting the three connections on one side. Each side has three connections. Be careful not to short anything out here. I only sparked this battery once! :) I've used the locking tab to prop up the battery.
Close-up of the circuit board with it's connectors to the charger or tool.
After you cut the final three connection points on the other side of the battery, you get a nice collection of bits you can throw away or recycle.
After removing the paper insulating tape, this is what you have. This particular pack has all of the cells functioning. They only need to be recharged and they are all set to deliver 18V at 3A. Thanks Doctorbass!
Doctorbass also has complete step-by-step instructions on how to dissect a 1.5AH pack and harvest the individual cells. LOTS of pictures and very clear instructions here: