I'm here to guide you on how you can delete an unnecessary report. This way, you'll be able to update your list of memorised reports in your QuickBooks Online account.
To delete a report, let's go to the Custom reports tab to view the list of your customised reports. I'm here to guide you how.
Go to the Reports menu.
Select the Custom Reports tab.
Find the report you want to delete.
Click the Edit drop-down arrow under the Action column.
I've attached a screenshot below for your reference.
If you wish to send a report via email at the same time and to the same people, you can add it to a group and send it on a recurring schedule. For the detailed steps, kindly refer to the How to set a schedule and email information for a memorised report or group section on this article: Memorize reports in QuickBooks Online.
Please let me know if you have other concerns. I'm just around to help.