RV Repair: how to fix hi lo trailer, kick plate, pulleys

Question
how do i fix the cables underneath the trailer and how do i get it to go up in the air to do it?

Answer
these cables run under the front kick plate you use as a step, as you enter the beds.  they also run along the side opposite the entry door.  they are on pulleys and these pulleys rot or corrode.  they twist and break causing the cables to come off the track.  the roof is heave and being down while this happens is tough.  will any part go up, or try to?  You will need a person who is strong at each corner, to lift.  once the lid is up, use 2x4 boards to prop the lid in place while you work. this is a big job but not diffucult.