How to clear out envelope numbers for Selected Members
In the People Module, select Quick Update then choose the Update by Search Criteria.
This is a list of all the members who have an envelope number that is greater than 0. If you want to allow any of them to keep their current number, you would delete them from this list. Otherwise, click [Next]
This next screen allows you to select the field you want to update. You will mark it to the left of the field and put the desired value in the Change to field. In the case of envelope numbers, you want to change everyone to 0.
There will be a series of screens you may ignore after this one by simply clicking Next until you get to Process
Click Next …. Process
Once you have done this, all of your envelope numbers are set to 0. You may now re-assign them, either through quick update or manually.