I've replaced the front sight on several of my guns. Somewhat recently, I put a Meprolight on my Sp101, a Hi-Viz fiber on my S&W 625MG, and just this weekend, a Williams Firesight on my Marlin 1894 levergun. Its quite easy to do. I'm not familiar with the Blackhawk personally, but I'd expect it to have a pinned front-sight just like all the others.
Simply use a pin-punch (available at hardware stores), probably size 1/16", to knock out the pin holding the sight. Then gentley tap out the sight. My Sp101 sight came right out, the 625 took some encouraging. Put the new sight in place, clamp it, then drill through the pin-holes from either side, alternating. Go slow and steady, drilling a tiny bit then going to the other side. The soft material of the sight will drill easier than the hardned barrel, so no need to worry about damaging the gun. Alternate back and forth from each side until the hole goes through, then neaten it out with the bit if it looks sloppy. Then just drive the pin back in. Should take all of about 10 minutes to change.
I'd suggest getting a replacement front-sight pin if you are ordering sights. They are cheap and will save time if you happen to bend the original pin while taking it out. My Sp pin got a little mangled and I needed to replace it. The pin on my S&W was fine and was reused.
