If it's like mine for the 110 then you have tow plates that sandwich one chassis outrigger and bolts to the rockslider with 3 bolts about half way along. You have two tubes with them - these are to place inside the outrigger to stop you crushing it as you tighten up the bolts. Then you have to undo the bolt that holds the bulkhead to the chassis and slip the rockslider over that and use the metal strap to bolt the rockslider to the front outrigger (hole needs drilling)
I hope this makes sense to you?
Pob