Have a Stern GOT LE, it's been awhile (couple years) since I opened the backbox now I want to update the code via usb. I have both keys on the same ring. I have the correct key in the backbox, it fits all the way in but I cannot turn the lock now to slide the backglass up and out. It only moves a little. I was worried about turning too hard and cracking the backglass. Is it possible to remove the lock from the outside and inspect it or any other suggestions? I might play with it a bit tonight... was pretty certain the backglass was all the way down to not block the lock from turning.