ok great
i guess a couple ways you can do this, one with replaceing the brakes while they are still mounted on the brake plate on the atv, or with the brake plate off the atv.
the only difference here is takeing it off the atv you will need to remove the brake cables from the plate by unscrewing the adjusters off and removeing the wheel hub, by removeing the cotter pin and the nut off the axle. but this procedure can still be accomplished by leaving those items on.
after that, you must break free and looseing the two axle locknuts on the right side, the outer is just tightened onto the inner. so find a good solid wrench of that size to wrench the outer off counterclockwise. and a wrench to hold the inner while you try to loosen the outer. sometimes if you dont have two wrenches of that size to work with you will at least need one to loosen the outer nut while someone else can assist by holding the axle still. a good way of doing this is finding a bar, or pry bar and putting it between the wheel studs for leverage. it helps alot if the threads on the axle have been cleaned, and a spray lube, like wd40 or any other aresol lube.
that is probably the toughest part of this whole procedure. but once the outer nut is off. simply turn off the other nut the same direction as well.
after both are off, remove the washers that they were riding against. there are 8 bolts that hold the brake plate the rest of the axle houseing. those need to be removed.
then loosen the brake cable adjusters out(if not removed already) to where they have no affect on the arm that they turn.
at this point the brake plate is free from the carrier and can be lightly tapped off. please take caution to not break it, for it is casted metal. the brake pads are then exposed and i would assume self explainatory from there,
on reassemble, the inner only needs to be fairly snug. but the outer needs to be tightened onto the inner nut very tight.
i hope this can give you some right direction, please let me know if you have any questions or hangups about this, thank you