Just did this on my 1997 C3500 truck. I was replacing all the steering components. I started out mounting the bracket first too, but I didn't want to try forcing the idler arm in, so removed the new bracket again, the loosely connected the idler arm to both the center link and the bracket, then pushed the bracket down in place on the frame. I was able to see inside the frame from the holes in the bottom toward the front to guide my socket extension. Dropped a bolt inside, but it wasn't hard to fish out with a little magnet extension. Don't forget to grease everything after install, that bracket took alot of grease to fill.
