1981-1984 Official Honda ATC250R Shop Manual, Page 147Get this manual
ATC 250R
REAR WHEELBRAKEDRIVE MECHANISM
REAR BRAKE
REMOVAL
Remove the left rear wheel (Page 12-3)Remove the cotter pin and hub nut and remove the wheel hub
COTTER PIN LOCK NUT WRENCH 41 mm 07916-9180000 or COMMERCIALLY AVAILABLE 41 mm Remove the rear axle nutsRemove the tongued washer and rear brake drum