How to mod remixes into the game?

[LunarMango]

Hi, i've been playing a hat in time for a while now and i found a song that would be PERFECT as a remix for the rift collapse stages. the thing is, i have had no experience whatsoever in modding a game, so i came here to ask how i do it, as i can't find any explanation on how to actually do this.
thanks.

[Duckboycool]

Here's a steam guide with an older developer guide about setting up the remix, as well as the update that's been made to remixes (which will help if you want to replace all of the rift collapses) and help for the cosmetic stuff. https://steamcommunity.com/sharedfiles/filedetails/?id=1909849742