A lighter hammer spring is an easy installation. You may find that it will only work reliably with Federal brand primers after the swap though.
A bit of polishing here and there will help as well.
My advice would be to put a few hundred rounds through it, then take it apart and look for surfaces that rub. Stay clear of anything to do with the trigger/sear. They get better with use all by themselves anyway. One place that often rubs is the hammer against the frame. Look for rub marks on the side of the hammer. They almost always are there. Take the hammer out, put some 600 grit lapping compound down on a piece of flat glass and rub the side of the hammer in a circular fashion until the side of the hammer is smooth again.
The inside of the frame were the hammer fits could use a bit of smoothing as well. Brownell's used to carry a stone that fit the Ruger hammer slot perfectly, but last time I checked I did not see it. You will have to improvise in there. You just want to polish it, not remove and real amount of metal. Put down the file...Think 600 grit. Don't go overboard. If you didn't get it perfectly smooth you will see more scratches show up on the hammer a few hundred rounds later. If so, just go over it lightly again.
And, the best way to smooth up a Ruger is to simply shoot it