I had a similar squeak when mine was brand new. I figured it could not be the bearings that soon. When I took it apart I noticed a small bit of black rubber in the drum. I put a light ammount of grease on the seal and put it back to gether. I have not had a problem since. If yours does turn out to be the bearing, it should not be too hard to replace. Remove the wheel, the castle nut and the hub. Remove the brake drum. Disconnec the linkage from the rear brake and unbold the backing plate from the axel flange. The bearing in the backing plate is held in by a snap ring. Remove the snap ring, drive the bearing out with an appropriate tool, carefully re install the new one with a new snap ring and new seals. A small dab of grease on the new seals and reassemble. Torque the Castle nut to 101 Ft lbs. then foreward just enough to align the holes for a new cotter pin. Take your time and pay attention to what you are doing and you should have no problem.