When a sales rep leaves an organization, all of their deals can be switched to another sales rep in bulk.
To do this, a company admin or super admin can remove the Sales Rep role from the user's profile. Use the "Manage Users" quick link on the home page, or go to Your Roles > Sales Company > Company Users. Search for the desired user and click "Edit" on the right under the "Actions" column.
Scroll to the section User Roles & Permissions. Click on Remove under the Sales Rep role and a new page will open to allow the reassignment of deals. A dropdown menu will allow the selection of any other active sales rep in the company. Select the user to reassign the deals to and click "Make All Reassignments".