I posted some photos in the following thread. The cover's hinge has a narrow slot that opens to allow the very thin hinge pin to slip out. It does take a bit of effort to remove and replace. I would have needed some better macro shots to show those small, thin features. Careful with the waterproof gasket thingie as you grip the door.
Hello and good day CubbyJonson. Thank you for reaching out and for the inquiry. You may check the post of ff22 on post #2 on how to detach or remover the USB cover of the DJI Osmo Action. If you have any other inquiries or concerns with your DJI Osmo Action. Please feel free to post it here at DJI Forum. We are all here to help and support you. Thank you.
lvl.4
DJI team