If you want an individual or selection of students to re-do the assignment, we recommend deleting progress for each of those students. You can do this by individually clicking the triple-dot next to each student's name in the relevant Assignment Report and clicking "Delete Progress."
You can also delete progress for a group of students by clicking the box to the left of one student's name and the option to "Delete Progress" for multiple students will appear as an option at the top. The responses for all students who are checked will then be deleted.
If you want the entire class to re-do the assignment, you will need to re-assign it. This means going back to the problem set you assigned, and following these steps (Canvas, Google Classroom) . If you are reassigning the same thing, we recommend differentiating the name for students.