circuit breaker

I currently have my spa and guest house on the same 15amp circuit breaker. Everytime I run the A/C in the guest house, it trips the breaker. I am going to be installing a 1000W outdoor Sodium Halide light for the guest house. I definitely need more juice for this circuit. Can I simply disconnect the 15 amp breaker and install a 20 or 30 amp breaker in its place? If not, what is the easiest way to get more juice and how can a non electrician like myself do it? I do not think that I can put the spa and guest house on seperate breakers because the guest house feeds off the spa's circuit. I do not know, I am very electrically challenged.

 

Please don't take any offense to this, but Spa wiring is no project for the "electrically challenged." Any situation involving water and electricity can have fatal consequences if the installation is done incorrectly. And no, you can't swap that 15 for a larger breaker. Besides the A/C and spa should be own their own dedicated circuits. I would really advise having an electrician over there to take a look.