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I suggest for you to acquire & study a M6800 WSM aka tech manual. Drain hyd oil. Jack rear of tractor up then utilize blocks of wood to be sure rear of tractor can't fall. ""Carefully remove wheel/tire"" then unbolt axle housing from trans case,remove retaining snap-ring then slide axle out of housing. I'm not sure how to address the brake assembly!!! R&R defective parts then reassemble.