It can only be done on HG/SS, where you need a ditto, smeargle with the 3 moves you want to glitch+rage, and the pokemon you want glitched with mimic. In a double battle, mimic transform, then transform into smeargle, use rage until "rage is building" shows up, then ko the oponent with the pokemon that had mimic.
edit: Im breeding a flawless ditto and got a sassy onix with 31/31/31/x/25-31/?, when I find out the exact ivs I'll tell you since you were looking for a steelix =) Cant rng yet