to do it right,15 min. and one hole.the choice is yours on beads,there are tapered that fall out sometimes and the threaded type,the best of the threaded has a shoulder on it,you can only go so far and than it locks up,it is easy to twist off the beads if you are not carefull.we charge $15.00 for a center bead installation.it's easy to find center on a rib if you have the correct tool to do so,it's not good if you guess and botch it up,i have fixed enough of thoes from other people.one other thing that i hate to repair is scratches on ribs where the sight was screwed in and whatever was used scratched the heck out of the rib,use pin vises and this won't happen,don't use pliers.if need be use a piece of thin plastic with a hole and slot to protect the rib or barrel.it's not worth sending it to me to do,i am in the middle of the country and the shipping will cost more than the sight work,call your local smiths and ask questions,be as picky as you want to be,it's your gun.good luck.paul.
