installing night sights is very easy and doesn't really require a gunsmith, you can probably do it yourself and if you can't you can take it to pretty much any gun shop and they will install them for a small fee (around $10) or even free. As for doing check ups on your gun, you can also do that yourself very easily, just study up on your xd and get familiar with it, taking it apart, detail stripping etc. You can hit up some xd dedicated gun forums for all the help in the world, I.E. XD talk. google it.