Go to the company details >> select employer info >> change details >> select the assign company to box >> enter or select the persons name >> save

You can also assign someone by >> selecting the company >> click users (top left) >> add new user >> enter all details, you must complete all sections with a * >> save 

To un-assign a user #

Click users at the top of the screen >> on the user you wish to un-assign, click the drop down arrow >> next to the company you want to un-assign them, click the 3 dots >> click un-assign

If you wish to un-assign them from all companies >> under the user list, click on the 3 dots >> un-assign