How Do I Modify A Child Support Order In Jefferson County Alabama?

I have two children for which I am obligated to pay child support in the state of Alabama. My ex-wife has recently moved to Colorado. I am currently un-employed, though I am actively searching for employment. I would like to know whether or not I can have a modification to lower my payments while I search for a job. If so, who do I need to contact? The original order was from Jefferson County, Alabama, where my ex lived at the time. Since then, she has moved to two different locales so I am confused about which agency to contact and what to ask.
Thank you for your time.