This requires a character with positive reputation and medium to high commerce level.

Go to the first tavern you find and hire an officer. When the dialogue text comes up choose Isn't that to much? Keep selecting this choice until the amount you will spend for the officer is a negative number.

Repeat this process until you have the desired amount. You can lower this amount by a max of 1000 at a time with a commerce of 10. (Each point of commerce equals 100 gold).