I attached the angle using the bolts that hold the plate that holds the lines down. Just pull the bolts, put the angle iron on, and reinstall the bolts.
Grille Guard: I have replaced the zipties with 2 radiator hose clamps around the horizontal bar, placed as far toward the outside of the guard as possible. I found that I was hanging the guard on limbs as I backed up and it would break the zipties.
By using the radiator hose clamps and not tightening them completely the grill guard will swing forward when needed. In effect, the hose clamps act like a hinge. The guard can't swing backwards (toward the grille) because the Kubota grille guard stops it but if I hang a branch while backing up it will swing forward and off of the branch.
I do still use a zip tie on each side to keep the guard from being pushed too far to either side. I just replace them periodically when they get broken. I put the zipties at the very top of the guard and around the vertical braces and I do not tighten them very tight so they have some movement.
Bill Tolle