Restoring files

I hope I'm at the right place to post my problem. I just bought Active Sky 2016 with Active Sky Cloud Art. I already have Rex 4 Textures installed and I really don't know what to do before installing Active Sky Cloud Art. What should I do with Rex 4? Uninstall it? ...and if so, is it gonna restore my FSX files? Can I run both? What is the safest way to deal with that? Thank you