How to reset optional labs/assignment-to start over?

How can I reset optional labs, as if I never started them?

I erased some input, and I want to start over, how do I do that?

Can the same be done for non optional labs

Hello @EMILIA_TUGOLUKOVA @maria_paul,

Please check these instructions out which will ask you to rename your current notebook (optional lab or assignment) so that the system will be able to give you a new copy of it.