No shims at all. Just braces,brackets,nuts and bolts.How long does it take? depends on lots of thigs. How good your eye is to make it look right is the hard part. THey can be made to look right if you spend the right amount of time on them.
no bending! just loosen, adjust, tighten. Depends how small of a gap you want between the bumper and side cladding, i had to do some grinding to allow mine to slide far enough back for my liking, but just making it straight doesnt require mods.