Koy, you have to remove the wheels, then hubs/bearings by removing the large nut on the spindle. The easiest way to add the
brakes is to purchase the entire backing plate/hub/brake assembly and just bolt up using the 4 mounting bolts, grease and torque the bearings. You’ll then have to run brake wires from the trailer plug to the
brakes, and you’ll have to hook up a brake controller with wires to the trailer plug. After all is assembled, you’ll have to adjust the
brakes. As a heads up, my Scamp had the “leading arm” configuration, so the Left side and Right side brake assemblys have to be switched to their opposite sides in order to operate properly (I got that tidbit from Scamp Parts department when I ordered them). You could make it really easy on yourself and hire it done.
Best of luck.
Dave & Paula