If you see a folder inside another folder with the same name, you have an extra layer. Cut the inner folder and paste it into Mods , then delete the empty outer folder.
If a mod is only available on Steam, you can use external tools to download the files: the binding of isaac repentance mods no steam new
Since you cannot use the Steam Workshop, you must download mods manually. The best source is the website, which acts as a mirror for Steam Workshop content. If you see a folder inside another folder
If you haven't: Beat Mom once vanilla. Save. Quit. Restart. Now the mod menu will be interactive. The best source is the website, which acts
This is the trickiest part for non-Steam users. You cannot download directly from Steam Workshop without owning the game on Steam. However, there are three primary sources.