I think the flash is bad. i want to replace it but it is on other side of pcb. how to remove pcb from metal case? i tried to pry it out but something is holding it from other side which is not visible.

My guess is there is a silicone stripe holding the base but still i wonder how will you replace mentioned one.

The mcu is visible and not a problem. this can be easily removed with IR welder. I don't have experience in removing the pcb from metal case. if i force it, maybe it will break.