Answer: To change/update your account details go to 'My Account' on the top left of your screen. Once you are on the page you can select 'Account details' and under this 'View Buyers in Company'. Simply click 'Show' on the buyer who's details you wish to update, to change and update the details for that specific buyer.
Once you have changed the details, please scroll to the the bottom of the page and click 'Save Changes'.