My question involves child support in the State of: Illinois and Virginia

My divorce was final in the state of Virginia back in 09 and my son's mom and son now live in Illinois. I currently live in Florida and feel that the divorce decree child support is extremely high for the state of Illinois. We did not do a child support order through the state it is just ordered through the divorce decree. Can I put myself on child support for the state of Illinois to override the divorce decree in Virgina?

I would greatly appreciate any advice where to start.