Things You'll Need
Instructions
Unload the XD40. Remove the clip and remove the bullet from the chamber. Point the XD40 at the ground. Pull the trigger to release the firing pin. Pull the release arm on the side of the XD40 to release the slide from the frame.
Remove the small securing screw using the gunsmithing tool kit screwdriver. Pull the rear sight from the frame and locate the adjustment holes.
Determine which way you need to adjust the the rear sight. Replace the rear sight to the frame and insert the securing screw into the hole on the rear sight that provides the correct alignment. Tighten the securing screw. Reassemble the XD40.