Maps on several projects, combine into one?

Hello there,

I currently have 3 large separate projects, each has one map, I’d like to combine those into one project (not one map, I’d like to be able to load maps individually), what’s the best around doing that? I have some Meshes that have the same names in different projects so I’m kind of afraid to just migrate and run into issues, should I rename everything first?

Any help would be appreciated.