How do you convert a single breaker box with a 220 amp breaker supplying a hot tub to a 110 volt 30 amp breaker supplying an outlet?

: Replace the main panel breaker feeding the subpanel with a 30 amp breaker if it is currently larger (50A typical). Then you should be able to change your subpanel's 2 pole breaker to a couple of single pole 30A breakers. Use one of the single 30's for your 30A receptacle.

: : : : IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB : SAFELY AND COMPETENTLY : REFER THIS WORK TO QUALIFIED PROFESSIONALS. : If you do this work yourself, always turn off the power at the breaker box/fuse panel BEFORE you attempt to do any work AND always use an electrician's test meter having metal-tipped probes (not a simple proximity voltage indicator) to insure the circuit is, in fact, de-energized.