Replace Dryer Belt

Can someone explain how to repair my GE dryer belt? I have taken the top and lower back screws out and cleaned and removed all of the dust, but I cannot find a way to get to the drum wheel to put the new belt on. There was also an L shaped rod I could see from the lower rear of the dryer and a black wheel on the floor of the dryer that was probably attached to the rod before the old belt broke. I could not find a bolt (even in the vacuum dust bag that kept it on), although I did find a metal washer, so there must be one in there somewhere. Thanks for your assistance.