Athennian allows you to remove a principal from multiple entities simultaneously, and here's how:
Navigate to the People tab;
Select the record of the person you would like to remove from multiple entities;
Navigate to the person's Interests tab;
Check of the box next to the affiliations you would like to modify;
In the blue banner that appears at the top of the screen, select Change Status and then select Outgoing from the dropdown list - notice that the Start Date and End Date fields are empty in the blue banner;
In the new window that pops up, select the Reason for the removal, select the End Date, and then add any additional Notes as necessary;
Select Confirm - notice that the End Date in the blue banner has been updated;
Select Apply at the far right of the blue banner - notice the principal's status update and End Date update in the list;
In the Interests > Principal tab of the person's record, you will see the new Outgoing status of the principal in each of the affiliations;
Follow the steps listed in the Generating Supporting Documents portion of this help article to generate the supporting documents for the removals in each of the entities.