Remove the 4 indicated red 3.0mm long screws from the corners of mainboard using a Phillips PH0 screwdriver.

With the eyepiece facing away from you, pull up on the main PCB from the left side and then pull it away from the chassis.

There is a plastic locking tab on the bottom of the camera that holds the mainboard PCB.

A replacement mainboard can be purchased from AliExpress here