To replace the rear brakes, remove the muffler, then the rear wheel. 1 nut on the axle and it comes off. The front axle bolt slide out and the hub for the speedometer slides out once the wheel is removed. Take a few pictures or make a drawing if you want.
You can also go to bikebandit.com for exploded views before you take it apart. 1st time plan on 30 min for rear wheel and 45 for the front. Difficulty scale of 2.5 on a scale of 10.