I was trying to make the coliseum glitch, but i cant make it, there is a consistent way to make?

You need an older copy of the game from 2015 to be able to do the glitch. Instructions on how to get this copy legally from Steam are in our Discord server linked on this game's sidebar. Once you do have the correct copy performing the glitch is relatively simple.

Im already on the discord, whitch chat has the way to get the old legit copy? I already have the recent one on Steam

It is a pinned message in the #rebirth1 channel.