How do I open an Oregon PowerNow lithium battery pack?

I have a dead Oregon PowerNow lithium battery pack and I can’t figure out how to open it. I removed all four obvious star-screws on the bottom.

• It won’t open with prying on the joints.

• I tapped the two halves lightly with a hammer but they won’t slide apart

• There are two holes in the bottom front that are probably “air” holes. In case they’re some sort of “catch”, I inserted a small screw driver but that didn’t help.

I’m experienced in rebuilding lithium battery packs so the repair isn’t dangerous for me.