This tutorial explains how to install the Service Desk App into a newly installed UM >= 7.45 through 7.51.
Starting with release 7.52, the Service Desk App is shipped with the regular UM installer and does not need to be installed separately. See Universal Messenger 7.52.0 (EN) for information on how to active the Service Desk App in an existing UM installation.
Install Service Desk App
...