how to remove a device you no longer own

In my list of associated iTunes devices two iPads show up, one of which I no longer own. How can I remove that device?

Follow the instructions in the article that sent you here. Do you need help with a specific step in the instructions?

I understand the instructions, but it says you can only remove an iPad or iPhone by using Settings on that device itself. I think one of the devices is an iPad I no longer own and can thus not access.