How do you reset the oil service light manually on a 1992 BMW 325i e30?

Do this at your own risk. Toward the front of the motor on the drivers side is a large black diagnostic plug with a cap on it. Undo the cap and pull it off. In the center is a hole shaped like pacman. The lid has a piece that sticks down into the pacman hole. If you don't see pacman you have the wrong plug. Surrounding pacman is two rings of holes, some with connectors in them and some without. Using a fused jumper connect the hole two spaces away (outer ring) and directly in front pacman's mouth with the hole closest to (inner ring) and directly below pacman viewing pacman's mouth to your right. Turn the key to the on position, in about 5 seconds the oil service lights should go out. Immediately turn the key to the off position and remove the jumper. Then test it by starting the motor, if the light is still on repeat the above steps.