From the ISU library homepage, navigate the main menu to "My Library Accounts" > "ISU Library Account"
Log-in using your 9-digit ISU Bengal ID and your last name.
Once logged in your account will display the items you have checked out.
Click the little box to the left of the item title, then you can "Renew Marked." Or, you can use the "Renew All" button to renew everything you have checked out at one time.