Have the factory install them. Tapping on the sight to "drift" it into those super tight dovetails can break or crack the vials in the night sight. Did you know S&W uses a hycraulic press to put the sights in their 3rd Gen and M&P autos? They are nearly impossible to move even for windage adjustment. Also, be careful when removing the rear sight as there are springs and parts held in by the rear sight, which will go south when you take of the rear sight. Those same parts and springs are awfully easy to damage when trying to move the new sight over the top of the the parts and springs that protrude when you remove the rear sight. Good luck.