I can’t remove the unit on the Doorbell Pro to access batter for charging battery
Welcome to the Wyze forum @eudnu !
Check out this post.
Once you have the doorbell unmounted remove the rubberized flap to expose the micro usb charging port on the back of the doorbell.
Once finished charging make sure to fully set the cover back in place so it cannot be comprised by moisture, then remount.
If you are looking for any additional information please let us know.
You are welcome.