In these photos, the buttons board is still on.

If only certain buttons are not working it may be appropriate to only replace the buttons board with play/pause and volume up/down. If you are having trouble with the power and bluetooth buttons as well, this step will allow you to replace those.

Use the metal spudger to again pull the board containing the power and bluetooth buttons off from the device. It is located next to the strap.

It's glued on, use necessary force.