Pretty simple, really.
Should you decide to fix it yourself and not spend the time waiting for shipping to factory and back...
Remove slide from pistol. Place on hard surface, but protect bottom of slide.
Remove rear sight from dovetail.
Take small to medium center punch and small hammer and centerpunch the interior bottom of the dovetail. You just want to raise up a couple pimples, not open up the firing pin channel.
Using brass or nylon drift and small hammer, replace rear sight in dovetail. Sight should enter from right side to left. Center the sight, check for regulation. (Take drift and small hammer to range next time for final adjustment.)
The pin punch marks will not be visible from the outside with the sight installed. (At the risk of being a twit, keep that in mind when doing the procedure and things will be fairly obvious.)