How to remove rear cover
Remove plastic cover from speed control port with pliers (optional) or remove the speed control cable if plugged in
If present, remove captive nut from speed control port using 10mm nut driver (This may not be present on newer spindles)
Using Torx 20 driver, remove screw from casing. Keep the screw for refitting.
Slide rear cover away from main body.
As you slide the cover off, it is common for the screw to fall out as you tip the rear cover back. Catch the screw - you will need it later!
Note the position of the speed wheel, remove and keep safe