Fixing my mistake

I haven't been able to figure out a way. What I have to do is write down in my notebook the results of the students who have done it, fix it, assign it again, and ask those students to hand it in again so that I can change their score manually. Apparently, these systems do not allow to make changes to a worksheet that has already been handed in without causing technical trouble. Deleting the results seems to be the best technical solution.

https://es.liveworksheets.com/search.asp?authorid=352169