It is possible to re-assign management of properties from one user to another without needing to edit each property individually.
Access the user file which is currently the property manager by clicking Settings on the green main menu, then Users and selecting the user to remove the properties from.
Click on the Manage Properties tab at the top of the page to view managed properties for this user.
Manage Properties Page
The managed properties will be listed by company. Use the green button to re-assign all properties for a company to one other user, or use the blue buttons to re-assign them one at a time.
Select a user to assign to
Select the user to be the manager of the property or properties and confirm by clicking the Reassign Properties button. The user must have access to the company and be marked as a property manager to appear on the list.