Auto body repair & detailing: installation step bar westin, model chevy, floor pan

Question
If I lossen body mount bolts are their nuts on the inside that I can't see

Answer
it depends on the make and model of truck, for example I put westins on my late model chevy in about 10 minutes. the bolts were not spinning,So the 17 mm nuts came right down easy. Spray the bolts with wd40 or a product like that they will come off easier. Without knowing the make of your truck I do not know. If they spin the bolt will found under the floor pan and or behind the seat directly above the body nut. it is a very east job to do, a novice should be able to do this in an hour. Any more questions write back
                       hope this helps Brian