How do you reset the service and inspection lights on an e30?

Construct a 10-15cm long fused wire. On pre-facelift (pre-1988):

There will be a semi-circular shaped plastic socket near the engine oil dipstick. Open, and place wire securely in the centre hole, and then (looking at the socket with flat side towards you) the other end in the hole to the immediate top right of the centre. On facelift (post-1987):

The circular socket will be near the engine oil dipstick or upper left of engine bay. Open screw top socket, and you will see a pacman shaped piece in the centre. Place one wire in the hole which is about to be eaten by the pacman, and looking from the left side of car, place the other end in the hole your side (underneath) of the pacman. Once you have double checked and checked again the wire is in the correct place, turn the key in your ignition. Wait 3/4 seconds to reset service lights. Wait 6/7 seconds and the service and inspection lights will reset. NB: If they do not reset or go back to previous after a few hours, you will need to replace the S.I. board batteries in your instrument cluster.