simple so just copy and paste the export_descr_unit file into a place than create a folder in "MY MODS" and than create another folder named "data" and than after that copy and paste and than in formation, for example the hoplite replace phalanx with shield_wall and thats how you do it than regenerate mod manifest in launcher and than boom you should have it

Would you be willing to show me via TeamViewer? That is a bit more complicated than I know how to do.