Once a contact is added, it appears on the Global Contacts screen (MS Exchange > Global Contacts), and the screen allows you to edit or delete the contact.
To delete a contact, select the checkbox next to the desired contact and click the Delete button.
To edit a contact, click the Edit link to the right of a specific contact.
Changing the status of a contact (disabling/enabling)
You can also disable a contact (this makes it inactive, but does not delete it from the system). This is referred to as changing the Status. You can always re-enable a contact by setting it back to a status of Enabled.
To disable a contact, select the drop down menu in the Status column, and choose the Disabled option.
Then click the Update button.
To enable a contact, set this drop down menu to Enabled, and click the Update button.