How to remove the battery?

[Nagual]

Stop laughing. The nice girl at Best Buy slapped the thing in there when she activated it and I've never removed it since, but will need to eventually.

Yes, I've looked at the quick start guide from the box. It's no help. I don't see a place to pry it out and I damn sure ain't going in there with a wedge of some kind and cause damage.

Help please. I'm sure it's blindingly obvious once you're told or shown how. Thank you.