Originally Posted by szmike
Question: never "staked" a nut before. Is it tricky?
Not really. Take a look at the nut on the sight now. You'll see that what's actually staked is the end of the screw flaring/spreading it out some on the end so that the nut won't unscrew from the screw.
It's fairly easy to do and, I'm pretty sure the kit (either the sight kit or the tool kit) has fairly detailed instructions.
The real trick is to lay the sight assembly (removed from the revolver) on its right side, have something solid enough to support the end of the screw, put the staking tool on the end of the screw after the nut is put on the screw (the screw comes with a small indentation on the end to aid in the spreading of the screw when you tap it), hold everything perfectly still, aligned and then lightly tap the end of the staking tool with a hammer.
It doesn't take much to spread the screw so I'd go easy at first and then, if it's not spread enough, tap it lightly again until you get it where you need it.
It's been a while since I've replaced a rear sight blade but it's not that difficult. Just take your time and go slowly.
I highly recommend a book by Jerry Kuhnhausen titled "The S&W Revolver - A Shop Manual" available from a number of sources including Brownells for about $24. It is worth it's weight in gold, excellent reading and explains everything you could ever possibly want or need to do to a S&W revolver.