You can ask for a renewal on an item through your ILLiad account. Once you log in, choose the item that you want a renewal for and click on Request Renewal. This request is sent to the lending library. They will answer back with a yes or no and ILL staff will notify you via email of their decision. If the item is already overdue, please contact the ILL staff at 860-832-3408 or firstname.lastname@example.org and they will make the renewal request for you.
For ILLiad specific questions, check out the ILLiad FAQ. Office hours are: 8am-4:30pm (Monday through Friday).