In step 4, the instructions say: "unscrew the two 2mm screws at the bottom of the tablet and open the ZIF latch". If you do it as described, you risk damaging the motherboard. Why?

When you unscrew the screws, you release the metal bridge, fixing the connector. Although this part will remain glued to the battery cable, it is not fixed in any way, so it can fall on the circuit board at any time. But until you disconnect the battery from the PCB, the components on the board are powered and the metal part can cause a short circuit and irreversibly destroy the motherboard.

This is exactly what happened to me. Unfortunately, the manufacturer has not published service documentation with a diagram and layout of components, so the only solution (and expensive one) is to replace the motherboard. So I recommend holding the metal bridge while loosening the screws, carefully remove it and only then handle the ZIF connector. It is even safer to cover the PCB around the connector with insulating material.

Nice guide, but warning!

If doing step 5, be very carefull. Guide says "unscrew the two 2mm screws at the top right of the battery", but not explains, what you are doing. So here is explanation: doing so you release the metal bridge, which is fixing the battery connector. After you unscrew the second screw, the bridge is not fixed in any way, and can sudenly fall on the circuit board.

I suggest to hold on this part and remove it carefully, because battery connector is still connected, so all components are powered. The metal part can cause a short circuit and demage motherboard. This is exactly what happened to me. Unfortunately, the manufacturer has not published service manual with a schematic and layout, so the only (really expensive) solution is to replace the motherboard. So watch out!!