I just wanted to know how hard it is to replace the front and back brakes on this ATV?

SS2

 

It's pretty easy. Take off the caliper mounting bolts and lift off the caliper. Push the caliper piston into caliper bore (slowly, with old pads still in place). Remove the pad retaining pin and spacer. Remove old pads, replace with new. Be sure to put aluminum spacer between the pads. Install the caliper and torque to 18 ft lbs. pump brakes, bleed if necessary. You can take off the rear wheel if you need more room.

Sorry that was just the back brakes.
Front brakes, remove wheel. Loosen pad adjuster 2-3 turns. Remove caliper from mounting bracket. Push caliper piston into caliper bore. Push mounting bracket inward and slip outer brake pad past edge. Remove inner pad. Reverse for intstallation.

Not much different than a car.