How to remove flags in account register

We are using Quicken Deluxe. The person who handled a data file before me put a flag on almost every transaction in the account register. I would like to remove them all. Is there any way to do this for multiple transaction at one time? I could not find one. Must I do each removal one at a time instead? There are at least a thousand of them in one bank account and many more in multiple credit card accounts.