If you're told to overwrite any files, press 'no' (I've had a few people reporting that pressing 'yes' might cause issues). Extract the files to your Morrowind root folder as stated in the Morrowind Rebirth readme. When you've completed the installation, please continue with Morrowind Rebirth. It's not compatible with Morrowind Rebirth.

You will also need to deactivate grass by choosing 'no grass' for both Vvardenfell and Solstheim. Now keep in mind that you need to tick the 'custom mod' option for each flora region. Start by downloading MGSO, then click the installer and follow the instructions until you reach to 'custom option'-screen. With that said, is Morrowind Rebirth compatible with MGSO? That depends! There are some things you need to do in order to avoid issues (though you may still experience some issues). Obviously there are some graphical elements in Rebirth, but these are mainly mesh-replacers, and are aimed to make the in-game models a bit easier on the eyes.

MGSO as you might have noticed by now, is all about graphics and sound. Rebirth is all about enhancing the in-game experience by overhauling cities/landscapes, by fixing bugs and balance issues, and by introducing new creatures, weapons and armor-pieces. Morrowind Graphic and Sound Overhaul and Morrowind Rebirth Clarification: Morrowind Rebirth is nothing like MGSO.

How to install morrowind rebirth