How do I open the case on the Theragun Elite to access the battery?

Hi everyone, I've come here for some help fixing a Theragun Elite.

To give you the backstory, as this may help out others, I bought this as a gift for my wife, but the device would not take a charge. We returned this to the retailer who exchanged it for another new device, but that had the same fault. Looks like there are hundreds of them with dud batteries.

Having done our research this is a really common fault and we were advised by the manufacturer that it would be best to replace with them directly.

What they did was send us out a brand new unit, directly and asked us to "dispose" of the faulty one. That doesn't seem like the right thing to do, so I wanted to see if I could do a repair on this and then give this to a family member.

However, I can't get much further than this (see pics)

I don't want to wreck the casing any more than I have done already. Any suggestions with annotations and arrows would be very helpful :)