I have a '86 535i. Yesterday I removed the instrument cluster and tried to access a small panel on the back side of it held with 4 screws. After removing the screws the board was still retained by the larger plastic cluster shroud. I was nervous about prying on it too much. Questions: 1) Is the SI board under the cover I described or where? 2)Is there a trick to removing that cover? 3) Can someone point me to a URL with some details on the whole process of changing out the batteries on the SI board? Thanks.