This can be tricky at times. There are certain debt consolidation programs that might be helpful though. They consolidate all your loans into a lower monthly payment.
You could also work on targeting your lowest bill each month; paying extra on it until you are able to pay it off completely. Once you eliminate it, then you could take the money that you were spending on it each month and target the next lowest bill with those funds. It can be a lengthy process to do it this way, but it eventually pays off in the long run. The more lower-level bills you pay off, the more money you can put towards larger bills in the future.