Now on to the main part. The first step would be to remove the board from the case, and prepare the modifications to attach the battery holder onto the case.

(1) This might be the trickiest part of the upgrade. The Ugreen case cover can be found on the bottom of the device, neatly glued. Carefully separate the cover sides with a paper cutter, then use a small minus screwdriver to pry off the cover. As you can see, I failed to preserve the beauty of it, but you might have better luck!

(2) Now carefully pull the board on its sides with a plier. Wiggle it a bit, as the case had a small board holder slot on the other end.

(3) Remove the power and volume buttons, by pushing the pins from the inside. I found it impossible to put back the board in later with these two parts on!

(4) Drill couple of holes with a small hand drill or soldering iron. These holes will be the opening for the battery holder wires.