Carefully slide out the electronics.

You can see a screen on a PCB in a black plastic frame.

Remove the PCB from the frame

Remove the black foam tape

Remove the two screws (redcircles) next to the USB-A connectors.

Carefully bend the plastic (pink rectangle) on the menu select button to remove the PCB.

If you have the FNB58B variant you should see the bluetooth module remain in the frame (green square).