Need some help

Joined a common market. Set up the requested amount in contracts in my enterprises.

I tried to be lazy. As new corporations were acquired, I went to the bottom of the common market contracts and input the minimum required percentage of my common market.

I didn't realize this was additive. I now have corporations offering way more then they can produce. I tried to reset this by offering a different amount in each corporation, but I can't lower it.

How can I reset this down to the values I want? Any advice appreciated.

Disregard. Figured out what the problem was. I had a corp that was offering more then it produced. Once I took care of that, I was able to reduce the rest of it down.