Your gonna need to pin point the leak, as for the bearings, take the link off the chain, pull the left wheel/hub off the axle, take the 2 axle nuts off, slide the sprocket and the hub its bolted to off, unbolt the rear caliper,slide the axle through the carrier. now you take the bearings out, I use a big worn socket extension I have tapping the bearings out from inside on the opposite side