Schritt 3 übersetzen
To make things a bit easier you can tin the tabs of the battery.
Place the battery on the circuit board (make sure you get the orientation right), put a small blob of solder on your iron and heat up the pad under the battery tab while applying some slight pressure to the tab. Once the battery is in place remove the iron and repeat the step for the other side.
You can now reassemble the cartridge and check if it works.