Online - On the library website go to Library Catalog. Select My Account in the top menu, log in with SC4 email and password. Navigate to the Checkouts tab, select title(s) to renew and Renew.
Call the library at (810) 989-5640, and the circulation staff will renew your books for you over the phone.
In person - take your library card to the circulation desk and ask a staff member to renew your books for you.
Circulating books can be renewed twice, and the renewal period is 3 weeks.