If you are mechanically inclined you should be able to do it yourself. Finding a hammer might be a bit of a problem however. You can install a Wolff spring kit that will reduce the DA trigger pull by 30-40%. Would you still need to change the hammer over to a spur hammer if the felt trigger pull was reduced by 40%? Check Brownells, Midway, Ruger, and Gun parts corp for a hammer, and midway or Brownells for the spring kit.