Depending on your authorization it is possible to change the Presence Status of other users. To use this feature the ACL Modify Presence has to be enabled for your ACL Group. Your administrator can provide you with more information or access to this feature if required.
Open Collaboration and navigate to your Colleague or Fn Keys screen. Right-click on a colleague and click Set presence. You can now change the Presence Status as it is your personal Presence Status that you are changing.