The easiest way is by logging into your library account and looking at the Loans tab. TheRenew option will be to the right of the title if a renewal is possible. Once you've requested the renewal, ILL staff pass that along to the lender, who has the final say on whether the due date changes or not. If the lending library says "no" to a renewal, you can make another request for the same book. We'll try to get it for you from another lender.
The book was due yesterday. Can I still ask for a renewal?
Call the Access Services Supervisor at 423-439-6997 or email firstname.lastname@example.org. Most lenders will still consider renewing a book that's only one or two days overdue.