I belong to that small minority of rifle shooters who appreciate open iron sights. Yes, they are tough to adjust - and you can forget about winning any matches - BUT nothing is as fast when you are trying to shoot something while it is still shootable.
They are also light, rugged, and snag free. They are a big part of why the sleek little 1894 leverguns are such a joy to handle and carry.
Current factory irons are rather basic, so I replaced those on my late production .30 WCF Trapper with earlier ones more appealing to my taste - a Winchester flat-top rear, and a Marble Sheard front.
Here are the required tools:
The bench vise with padded jaws, hammer and brass punch are essential, and the dovetail file (60 degree, true parallel with only one cutting flat) is nice. You can find these at Brownells.
With the little carbine stripped to its bare barrel, I drove out the factory sights left to right, as a shooter holding the rifle would see them, and tapped in the new ones right to left. File the sights (not the rifle) if you need to, should they not want to start into the dovetail. Use short sharp raps of a light hammer, and work slowly and carefully so that you don't mar anything.
Don't expect them to be "on target" - you will have assemble the rifle, shoot a group, measure, consult an online sight calculator, disassemble, and correct as needed. Expect this to take several tries before you are satisfied. Crude, yes, but that's how it's done.
The results are shown above. This 10 shot group was fired "field style", with a center hold. You can see that the spread is about 2 1/4", and that is the biggest complaint against open irons - that they are not very accurate. What you can't see is how you are looking right down the sights as the little carbine snugs into your shoulder.
The accuracy limitation (which is highly dependent on personal eyesight) is real. While the group shown represents 4.5 MOA, it was fired carefully, and in good light. 6 MOA may be a more realistic expectation, but within the little carbine's point-blank range, it doesn't matter.