How do I play high notes on the Trumpet?

Just gotta work on scales and lip slurs. Try improving flexibility in the lower register too. They say that to play high, you've got to play low. Don't force it either- if you work too hard or too long, you'll rip your lip muscles up and ruin your tone. Also, the break between C and D is a tough note, so it may take a little while to be able to slur up to it. Focus on pushing the air up from the bottom of your stomach. The more air that you push, the higher the sound. Don't get discouraged if it doesn't come straight away- give it time, practice, and it'll eventually be just as easy to play even double-high D as middle G. Good luck!

The first simple things you should do that help alot is first, move the mouthpiece up on your mouth so that the bottom of the mouthpiece rests on the brim of your bottom lip. Also, when you are hitting a high note, lift your tongue upwards as you play the note. This helps you because the air flow is less, less air flow equals higher pitch. Another thing that many people do but does not actually help is playing high notes loudly. The softer you play them the better. This is because the louder you play the more oxygen you are taking from your lungs and even though you might be able to hit the note using this method it won't help you in the long run because you're tone, (which for you is good apparently :), becomes pretty bad and you can't hold the note for that long. Another thing my band teacher has told me and has worked for me is trying to play really low notes. If you can hit low notes that are really hard to hit then hitting the really high notes becomes a lot easier. You should try octaves that include really low notes and really high notes. Those help alot to in cranking them out. Anyway, hope I helped you out and good luck on your new piece.