The sensor arm lamp on my Beogram 4000 gave up recently. I can see the filament has blown. I have a replacement. Can someone provide any tips or procedure to solder the new lamp in place? I can pull out the black plastic front of the sensor arm but there is resistance before I can get to the solder points. I don't want to stress any of the wires. Any advice from people who have accomplished this "'surgery' is welcome.