XD uses a locktite type adhesive on there sights. Its best to heat the slide up with a heat/paint remover gun. The sights can then be removed like other guns. You need to remove all the plastic parts and springs in the slide before you heat it up. Strip the slide bare, heat it up to 250 deg, and tap the sights out. I like to use an aluminum drift/punch instead of brass or steel. I also use hard wood pads in my vise to protect the slide.
Never believe anything you hear and only half of what you see