An old machinist showed me that trick 30 years ago.
No dings at all, just make sure you hit the sleeve only.
Alot of times, all it takes is doing it twice on opposite sides & it slides off.
Probably did twenty in my lifetime.
It expands the size of the tube by spreading the metal.
(When you hit the metal it moves toward the sides of the impact point effectivly making the tube bigger around.)
Have you ever seen a small hard rubber tire with a lot of weight on it when it rolls and the rubber part gets bigger around till it looks too big for the rim?
Same idea.