From the information you provided, you're in a tough situation. I do not know the laws of the States of Michigan or Ohio, so I'll briefly reflect on how this may be viewed by the Washington Courts.
First, you can move the Court(s) to modify your child support agreements. You will need to show that you have had a "substantial change in circumstances" before the court will grant a modification. The Courts are also driven by whatever is "in the best interests of the children."
Because you are going back to school for additional technical training you will probably be viewed as "voluntarily under-employed" during school. As such, the Courts may find that no modification is warranted and deny your petition.
The Court process is expensive and time consuming, and it appears you'll have to do this in two separate states. It's likely that even if the Courts grant you reduced child support payments during your 9-month program it will cost you more to have your support payments modified than any estimated savings to you.
Your best option is to discuss your situation with the mothers of your children and ask them if they will voluntarily agree to lower payments, or voluntarily agree that you'll make up the payments in some way after your graduate and are re-employed. This won't cost you much, if anything, and you can sign an agreement that you and each of the mothers find acceptable, and that is enforceable in case any party doesn't fully comply with the agreement.
Good luck, Mark Arend.
Second, depending on your situation