Rae Sremmurd's Slim Jxmmi Getting into Boxing After Domestic Violence Case

Slim Jxmmi is making the transition from music to boxing -- he's preparing for his first match, and already looking to get in the ring with a bunch of famous opponents.

We got the Rae Sremmurd rapper after he finished a training session at Dogpound Gym in WeHo, where a ton of celebs work out, and asked why he's getting into boxing.

Slim says he's turning 30 and wants to make some changes, set a good example for his kids, and as he put it to our photog, "Be done with the stupid s***."

Along with making big life changes, Slim is mending fences.

As we reported, he was arrested in January for the alleged battery of his then-girlfriend -- but she's since recanted, and the case was dropped. He tells us everything is cool between them now, and he intends to take care of her for life.