I have a Trijicon front sight post. Installation is easy: Unscrew old post (don't lose detent spring) screw in new one.
What are you planning on using your rifle for? I have found that the night sights were not so useful. For anything out past 10 yards, the flashlight was on for identification purposes anyhow which washes out the glow from the sight. Inside 10-15 yards, "sighting" is done between the ears of the sight base without the rear sight, and I don't use the post anyway. Just some info as most front illuminated front sights are upwads of $50 which might be better used somwhere else on the rifle.
"People live too long, dogs don't live long enough" - FTF Member-