There is really no good way to increase your range quickly. There are some things you might be able to do to get you playing a little higher, but not without sacrificing your lower register, tone, flexibility and intonation.
If I were you I'd spend more time playing in the lower register and mastering your sound. Believe it or not, that will help with your range. It won't happen over night, but you will sound better in the long run and improve the right way.