If S&W makes a white outline rear sight blade in J frame size, it's fairly easy to install it on your revolver; IIRC J frame rear sight blades are a slightly different size than the more common K/L/N blades, but I could be wrong about this.
Swapping the rear blade is not what I would call difficult
but it DOES require special tools. From an earlier post of mine...
...the job isn't necessarily hard, but you'll need a couple of special tools and a replacement windage adjustment screw and nut; however, the sight blade kit should come with [the screw and nut].
The windage adjustment screw has a countersunk end that is staked to the nut to retain the screw within the sight base. The screw is removed by tightening it until it snaps, then unscrewing it out of the sight blade. To reinstall, you use a special forked tool to hold the nut, tighten it down, and loosen it 1/4 turn to allow it to rotate. The screw is then staked to the nut with a pointed punch. The special forked tool and the punch are available direct from S&W and from companies such as Brownell's.
1) There is a little bitty spring and plunger on the side of the screw head to provide the "click" micrometer adjustment; these parts are very small and WILL come flying out as the screw is pulled out of the sight base, so be ready to cover them with your thumb, or disassemble the parts inside a plastic bag. [EDIT: some people advise ordering spares as they are relatively cheap.]
2) S&W rear sight blades come in several different heights. Using the wrong one on your revolver may mess up the elevation adjustment range. I recommend calling S&W customer service so they can look up which sight blade is on it now. If you don't do this, you may be the guy posting on this forum to ask why his revolver hits 6" high @ 15yds with the elevation nut cranked all the way down.
OTOH I have been advised not to try installing a pinned S&W front sight myself because the hole for the pin must be drilled through the new sight while it's installed in the barrel
. Without a drill press and a good deal of skill using it, IMHO this is best left to a gunsmith.