Undo the 17mm brake side axle nut ,(Right side while facing bars) remove the nut, then the washer, the wheel, then the depending on the unit the spacer, and "o"ring. (on some later units the spacer is held in by the outer brake shield) in either case, remove the brake shield (Three 10mm bolts) All items should slide off fairly easily from the shaft, there are no hidden clips that I know of. The brakes should now be exposed. if you are un-sure of what to do from this point, be sure to take plenty of pictures, as brakes are a handy thing to have.
Jim