Assign each of the parts to the students. Many conductors will hold auditions for chairs, giving the harder parts to those who play the music better. You may want to test the students on the 9/8 rhythmic measures in the Emperata Overture, due to their possible difficulty during performance.
After you assign "seats," pass out the sheet music to the appropriate sections.
Practice running scales for the key of the music. Do this until the students familiarize themselves with the key of the music.
Emperata Overture is written in the key of C major.
Run through the whole of Emperata Overture, stopping the music at difficult parts for the band. Note those parts where sections have difficulties. For example, if you notice that the trombones have difficulty with measure 53, make a note of this in your conductor's manual.
Break each group off into smaller sections every other day, basing the size of each group on the size of your band and the number of instructors. For example, you may want to section your groups like this: low brass (tubas, trombones and baritones), trumpets and French horns, clarinets, flutes and piccolos and saxophones.
Each section then practices those movements that you assign to them, based on trouble shown during full band practice. Many bands use after-school time for section practice.
Continue to fine tune the music, beginning with note memorization, then moving into the movement of the music, focusing on speed, volume and tonguing elements, like staccatos and legatos.