For more information on how to de-activate a co-worker, click here. If you need to re-activate the user for whatever reason, simply navigate to Settings > HR, where you'll find a list of active users (by default).
At the bottom of this page, you'll find the button "Show inactive users".
When you click on this button, inactive users will be displayed as well in light grey.
You then click the pencil on the right hand side, under "Actions", to proceed to the following screen. You'll be able to reactivate the user by switching the slider to "Yes".
As soon as the slider is set to "Yes", a new screen will appear allowing you to edit the user. Just define the settings as you see fit and click "Save" to proceed.
Customer support service by UserEcho