Forcing a regrade

[ClaireMThomas]

I have an multiple choice exam (old quiz). I set it up to give the average of two attempts. There was a technical snafu that required an extra attempt be added (all done and managed, quiz is closed). Now I want to change it to give the highest score. I edited the exam properties and saved, but no regrade happened spontaenously or was offered. How do I get the regrade to happen?