The flap is basically a squared off U shape. In these pictures the hinge is at the bottom and the closed end of the U is at the top. You want to hinge it up so it's vertical. The cable connector will pull out towards the bottom of these pictures. It seemed to help to angle it towards the bottom of the phone a little to get it out of the socket. Same in reverse to put it back in.
The metal piece with white and black areas stuck to the adhesive and pulled off the board for me. There are some chips under it. It popped back on the board and didn't seem to be a problem.
The battery connector is attached to the battery. You're not going to completely lift it out and remove it. It pulls out from the socket you can see in step 5 picture 3. The pressure contact (little black and gold thing) will probably just slide out from under the connector. Not a problem.
