Shouldn't be too terribly hard to do, even at home.
Ruger will sell you the 3" stainless ejector rod housing. The front sight can be sweated off with a torch and reattached with silver solder or a screw fit. Pacific tool and gauge offers an all in one tool to true and cut a recessed crown on the barrel after it's been cut. I bet once you had all your tools and parts together it could be done in a weekend.
This progressions off a couple builds but you'll get the idea
Drill and tap
Chop the barrel and crown
Reattach front sight
Put her back together and have at it.
A bit over simplified but if you search out my build threads there's a lot more detail.