Changing out the sights yourself can be done, but it will require removing the manual safety body from the slide, the purchase of some equipment, and learning as you go, whether you use a sight pusher or a hammer/punch/vise method.
If you don't plan on doing it again, it might be easier to simply use a gunsmith or send the slide to Trijicon for installation. If you do plan on doing it again, here are a few pointers:
- The sights drift out to the right (ejection port side), and the new ones drift in to the left.
- There are 2 plungers and springs underneath the rear sight that can pop out when removing, and require some finesse to put back in when installing without damaging the springs.
- You will likely have to remove some material from the bottom of the sights to get them to start to fit. Do not remove material from the sides. The sight bases are meant to be tight and are softer metal that will conform a bit to the shape of the dovetail. If you don't remove enough material it's possible to get the sight stuck in halfway. That's a lot of fun.
- You'll want to center both sights in the slide, so having a digital caliper helps.
- Using a sight pusher is safer for the tritium vials and easier to be more precise with the placement of the sight in the dovetail, but more time consuming getting everything lined up.
- A hammer and punch in a padded vise is quicker but less precise, and it is possible to crack the tritium vials with too much force (though I haven't actually done this yet, and I have beat on some night sights). I prefer to use a hammer/punch in a vise with strips of 2-3oz leather on either side of the slide. I use a 36oz deadblow hammer (Estwing Compocast Ball Peen) and a long 1/4" brass rod with a beveled & flattened end for my sights.