I wouldn't have thought it would be any more difficult than removing the rear wheel to deal with a puncture, apparently the bolts from the swinging arm have to be removed and the whole arm dropped down below the level of the fuel tanks so the long centre bolt can be removed, the drive pulley then comes away with the wheel, so I'm told! More to the point, I wonder what the cost of a replacement belt will be, I'm guessing around £100? Should a three wheeler owner always keep a spare belt in the car?