How to practice a hard piece of music

Seat yourself with your piece of music and your instrument.

Begin by warming up your instrument and getting mentally prepared.

Look over what you are about to play.

Count rhythms out loud and clap them with your hands.

Look for the accidentals and the key signature and begin to play the notes and rhythms very slowly. If you are having trouble slow it down to where you can play it.

Continue this process till you can get the notes and rhythms down perfectly. Work on putting in articulations.

Once you add these, play through it a few more times.