Thanks for the guide. I replaced the battery (official LG replacement) last week and so far everything is working properly. Overall it’s not difficult. The only step which is a bit more challenging, is removing the battery itself as it’s “squishy” and the adhesive is rather strong.

But nevertheless I would only do it if really is needed & make sure to take enough time to follow the process carefully. After all it’s clear the phone is not made to dis/re-assemble often as it has a lot of fragile parts (in particular in step 5)