Help with merged files??

Does anyone know a program besides s4s that lets you un merge or edit merged packages? Or maybe some other way to do it in S4S that I’m missing? I’m trying to clean out some cc and realized I have several merged files all at least a full gig with stuff that wasn’t even supposed to be there like build buy items in a giant merged file from a sim download. I was able to un merge a few through content manager but the others I keep getting a popup saying it’s either not merged (definitely is) or it was merged using a version of s4s that doesn’t support un merging. I can edit each file, remove swatches, etc. in s4s while it’s still merged but if I try to delete a file it deletes the entire merged package instead 🤦🏼‍♀️ Not sure how to fix it at this point. I need a way to either un merge them or delete specific files while it’s still merged. Is there a way to do that?