Hello. I owned one of these bikes before for 3 years. You’d want to disconnect the main wire plug that leads to the rear motor. It’s a fat cable, disconnect that, ensure the power is off first from the bike. There’s a left and right bolt covered by a black plastic cover, remove the cover and untighten the bolts. Secondly, before taking off the tire, remove the chain off the stakes in the front of the bike and move the chain to the clear left away from the chain stakes where the chain rest on the gears to shift. Lift up the rear back of the bike, pull the tire out and make sure you get the rest of the chain off the gears in the rear. You’ll also need to remove the back shifter too. Repeat the process backwards to put back.