How to open the phone?

[quixote]

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.

Can't get the gap to open on mine *at all*. All I have is my fingernail, which doesn't seem to be strong enough for the job!

This means I can't get an sd card in and I'm dead in the water with my lovely Braveheart.

Help!  What else can I try? Are there special tools to safely pry these apart? A really thin knife to try it unsafely?

I used to have a Nokia 900 which worked much the same way, but that one started releasing the little "catches" on the inside of the case as soonb as you got your fingernail in the gap.