How do you edit the version of a game that’s currently up?

I broke my roblox game while trying to make an update for it and the two main things that the game has to work are broken. I don’t know why they don’t work and what broke them, I think I deleted something I wasn’t supposed to.

I’m thinking I can publish the models and scripts as models on to marketplace as private, edit the not broken version and put everything back there. The thing is, the version that I’m working on for the update is the thing that pops up when I want to edit. How to get to the published version and put everything there? If you help me with this, thanks.

If you wanna try the game out it’s called Lava Escape, the easiest way to find it is on my favorites.

(This entire question looks like its writen in code when previewing and I don’t know why)