There are two small 1/4” pins inside the “caliper” they get rusted up. Jack up the rear of mower between rear tires. Remove the right rear wheel to access the brakes, you may need to use a heat gun to get the dust cup off to remove the washers and clip. Remove the washer and cotter pin from the brake line. Remove the two outer bolts (on either side of the caliper) and slide /remove the caliper from the mower. Place the brake pad and backing plate off to the side. On a workbench remove the spring, and center nut — then slide the washer and armature off the caliper. Clean dirt, grass, and goop off the caliper with brake cleaner. Soak pins with penetrating oil like PB Blaster. Use a hammer and tap the pins with a scrap/spare bolt, and gently work the pins back and forth until you free them from the caliper. They will be rusted up. Use steel wool, penetrating oil and some 500 grit sandpaper to clean the pins and the inner holes on the caliper. Clean the entire unit. Then apply a generous brushing of anti-seize...