Search for the contact you want to archive by using the "Jump to contact..." search bar and click on their name.

Once on the contact's Dashboard, take a look at the contact's yellow sidebar on the right.

Next to the contact’s name, there are two icons, a printer and a file storage box. 

Click the icon for the file storage box to archive the contact.

A confirmation will appear in your browser. Click OK to confirm.

A message will be displayed briefly above the dashboard confirming that the contact is successfully archived.