Your inner brackets are mainly up and down adjustment. Take the outer brackets right off, have the 2 inner inner ones semi loose on the frame, set the bumper on them and check your up/down alignment as well as in/out spacing from the grille. Once happy snug the brackets to the frame. Then shift bumper side/side until happy then snug the 4 bolts in the center down. Now the fun part, install the outer brackets, get all 4 bolts in loosely before snugging them down on both sides