The cluster is easy to remove & so is the gauge just don't forget to disconnect the battery. On the 535i just back out the two bolts that hold the steering coluum in place about 1 inch after removing the lower dash pad & padded plate. This will give you enough clearance to slide the cluster out the left side while you hold the steering wheel down & turn it to the left. Don't bother opening the back cover of the cluster. Just remove the 6 bolts & pull off the two knobs from the front. The front section with the gauges will now come off & you can just lift out the gauge.
02 R1100S, 87 R100S
76 R90/S,73 R75/5
Alfa Romeos- 65 Giulia Spider Veloce
& 66 Duetto 1600 Spider