you have to heat up the the ramp with a propane torch as the sight is soldered on. The factory sight also has a small post that fits in a hole on the barrel. If you do this yourself or have someone else do it I like the Weigand base which you can get from Brownells or Midway. The Weigand will use any of the inserts for the S&W "Classic" models. To install the new one you will need a way of holding it in place (I have a special installation tool) and keep downward pressure on it and you'll need a good quality silver solder. I use a paste I buy from Brownells which is a little easier to work with but you can use the wire form or they also have flat strips. When heating the barrel it would also be best if you get one of the heat absorbing pastes to cover the surrounding areas and inside of the barrel. It's not super complicated if your mechanically inclined and have done any soldering with a torch but there are a few things you need to buy so it becomes a case of do you want to make the investment so you can do other guns you may have or spend the money on a gunsmith. I did see Midway offers a screw on replacement base for rugers that you would have to drill and tap for but the base jumps from about 35.00-40.00 for a solder on to close to 90.00 for the screw on. I know that was long winded but I hope it helps.