Before starting any work on the bike, make sure the bike is turned off and the battery is disconnected. On later models, you can uncouple the clips from the battery, negative first (black), then positive (red)If you have the model where the motherboard is visible inside your controller please be very careful not to drop any bolts and washers or make contact with any metal tools, as this could potentially damage the controller.
You will need: 10mm, 19mm & 22mm spanners
Wrench set 8mm to 19mm: https://amzn.to/2LBvhdQ
Also useful: A short stool or work stand.
First, ensure that the power is off by disconnecting the magnetic kill switch then secure your bike on a stool or stand. Loosen the bolts on the rear wheel (it is not necessary to remove them), the drive side bolt is 22mm and the non-drive side is 19mm. With a 10mm spanner, adjust the bolts shown in the picture below to move the wheel forward to loosen the chain, it is important to remember to do this equally for both sides, otherwise, you may misalign the wheel.
Tools you need: Torx T25 bit and a 6mm Hex key.
Remove the controller cover using a 5mm hex key and disconnect the small led light.
You will need to remove the motor wires from the controller.
Tools you need
Once the top cover and battery have been removed you can open the controller with the 3mm Allen.
First Remove the battery cables from the controller using your 10mm spanner, negative (black) first, then positive (red), use your electrical tape to isolate the ends of the cables.
Then, using your 8mm spanner remove the blue, red and black motor cables.
Start by removing the 4 bolts on the motor using a 4mm hex key. Be very careful not to lose the 4 spacers behind the cover plate.
Remove the chain from the front sprocket, and remove the last two bolts holding the motor to the frame, and slide the motor out of the frame, be very careful not to pull or put to much stress on the wires going to the motor when removing it from the frame!