If your students are working in Mixed Review, and you'd like to have them complete a previous assignment,
Choose the class from the left column.
Go to Assignments in the middle column.
Click to make the previous assignment the default. (Make sure the assignment is available.)
Students who have not completed the default assignment will see this message. These students are now working on the default assignment and will transition to Mixed Review when they complete the assignment.
Students who have previously completed the assignment will remain in Mixed Review.