I use the same procedure as 44 AMP. I will only add a couple of points.
When you lay your barrel in the upside down slide, make sure the link is pointed toward the muzzle end of the barrel.
If you look at the left side of your pistol, you will see a metal tube, the plunger tube, that contains a spring (plunger spring) as well as a metal plunger that pressures the slide stop on the front end, and the thumb safety at the rear end. Sometimes on a new model 1911 the plungers are kind of tight and application of one small drop of light oil into the front end of the plunger tube, and pushing in on the slide stop plunger a few times will loosen it up and make reinsertion of the slide stop a bit easier.
The so-called "idiot scratch" is a mark on the frame resulting from incorrect insertion of the slide stop. I wager that most model 1911 owners own or have owned at least one 1911 pistol that bears an idiot scratch. It is a rite of passage of sorts. What you don't want to do is insert the slide stop lever all the way in and then try to rotate it upwards against the pressure of the slide stop plunger. Instead, insert the slide stop with a simultaneous inward and upward motion so that the slide stop plunger gets pushed back in the plunger tube before the slide stop lever can contact the frame.
When you lay your barrel in the upside down slide, make sure the link is pointed toward the muzzle end of the barrel.
If you look at the left side of your pistol, you will see a metal tube, the plunger tube, that contains a spring (plunger spring) as well as a metal plunger that pressures the slide stop on the front end, and the thumb safety at the rear end. Sometimes on a new model 1911 the plungers are kind of tight and application of one small drop of light oil into the front end of the plunger tube, and pushing in on the slide stop plunger a few times will loosen it up and make reinsertion of the slide stop a bit easier.
The so-called "idiot scratch" is a mark on the frame resulting from incorrect insertion of the slide stop. I wager that most model 1911 owners own or have owned at least one 1911 pistol that bears an idiot scratch. It is a rite of passage of sorts. What you don't want to do is insert the slide stop lever all the way in and then try to rotate it upwards against the pressure of the slide stop plunger. Instead, insert the slide stop with a simultaneous inward and upward motion so that the slide stop plunger gets pushed back in the plunger tube before the slide stop lever can contact the frame.