I believe what you are asking is to do a interest rate reduction loan with the VA or an IRRL. This will lower you monthly payment amount, but not add any significant amounts to your current principal loan balance. To do this you can contact any mortgage professional who has the ability to do VA loans. As long as you are saving money on a monthly basis and do not have to pay more in origination/discount points than you will save over a 36 month period in your new loan it is a pretty easy process. No appraisal is needed, however you do need to be current on your mortgage payments.