How to open the phone?

[SpoofyKid]

Edit 5 min later: Well, a knife point worked to get the gap started. Then I used my nail. Still *very* tight and took a lot of coaxing. I think people will need a heads-up to expect this when the general-user-version goes out.

Mate, you're scaring me. There is a notch, specifically there to place your fingernail into (or a blunt and soft tool). You do not need to create a gap! Sorry, I'm not yelling, I'm just trying to make it obvious that there is a purposely made notch to separate the back cover from the phone. It is a bit rigid, but it's all pretty tough, so shouldn't break by you tugging on it.

See this photo, it's on the bottom right of the phone/back cover 
  IMG_20200613_173147~2.jpg (Size: 191.59 KB / Downloads: 329)

I hope this clarifies things