Can't remove power button after teardown

I want to strip and reanodize an iPod Nano 6th gen. I have several of them and have torn them down completely but can't get the power buttons out of any of them. The buttons move freely but can't be removed.

The +/- button drops out after removing the small internal frame but not the power button.

I don't want to strip and anodize with the button still in the case. How to get it out without breaking stuff?

Mark