Right, you can indeed install it yourself.
Once you do, check for "transfer bar pinch":
* Unload the gun.
* Check again
.
* Bring it to full cock, and then lower the hammer while continuing to hold the trigger back.
* With the trigger still back, push on the back of the hammer.
* Release the trigger, slowly.
If the trigger "sticks" backwards, the hammer is "pinching" the transfer bar - basically, it's hitting the transfer bar with more force than is necessary. The hammer should glide forward as your finger comes off it, even with the hammer pushed forward.
Many of us suspect this is a factor in transfer bar breakage. User "Flatgate" on rugerforums.com is the first to come up with this theory.
When you have a Ruger that's "pinching" like this, the cure is to gently file at the area of the hammer that hits the transfer bar, until the "pinch effect" stops. You can do this without taking the gun apart - wrap a small bit of rag around the base of the hammer to prevent grit falling in and gently file on the area of the hammer that hits the transfer bar. Go slow, PUT DOWN THE DREMEL, check it every dozen strokes or so of a jeweler's file.