"Loan Modification" - you need to ask your bank
some banks may need to charge for a fee called "loan modification" - after you pay into principals - to reduce monthly payment (also the interest, maybe).
Check with your bank and ask to talk with a specific mortgage officer/Senior manager.
Wells fargo charge it. It is about $200 - $300.
It is bullshit fee to me. But I feel bank need to make money also, probably most banks in USA charge that.