The way I was taught is to line up the link on the barrel and insert the slide stop, with the lever end hanging in the trigger guard. Once you have the link captured, simply lift the slide stop up slightly, so it doesnt drag on the frame, and align it with the slide stop plunger on the frame. Then push the slide stop home.
Occasionally, youll get a gun that the stop gets hung up on the plunger, and you might need a small tool/screwdriver, ect, to depress the plunger slightly, and it will go right in after that.
No chance of dragging the arc, if you dont push the slide stop against the frame trying to get it in the gun.