Click Your Name in the upper right hand corner
Click My Team in the drop down menu
Click Show Archived
Select which user you'd like to unarchive
Click Unarchive User
If there is an available seat then your billing will not change when you unarchive that user. You can see your seat count on the right hand side below the Add new user button.
You will be prompted to confirm the new billing amount if there are no additional seats available. We strive for billing transparency and so we outline exactly what you are paying for and when before you confirm payment.