Hard, but can be done.

Mein Problem

I was getting a 'Check Battery / Service Battery' notification.

Meine Reparatur

Far from perfect, but everything is working fine touch-wood.

Mein Rat

Instructions could include visual examples of screw types, as there are a few that differ in millimeters, which is hard to tell for a novice. I was left with 3 screws in hand that didn't make it into the assembly.