Navigate to: My Admin > Clients > Select a Client
You will have needed to import/manually set up both Clients and Contacts through My Admin.
Head to the navigation above, then into one of your clients by using the edit button. Once there click on Contact Links as shown below
Next, select Director as the Contact type, then select the Contact you want to link as a director and enter all required fields. including date of appointment.
If you want to link multiple contacts to a single company, use the Bulk Contacts option instead. There, use the checkbox(s) to select the Contacts you wish to link, select Director from the 'Type' drop-down menu and again enter the date(s) of appointment.