Log in to your Admin CP and go to the Components tab -> (FSY22) Universal Mod Installer -> Manage Mod Installations page. Look for the entry for this mod, click the grey Options button beside it, and click the Install link. The installer script will read the mod's XML file and determine the proper installation steps, then you can click the Proceed button to have it execute these actions.

Log in to your Admin CP and go to the Components tab. There will be a new section in here entitled (FSY22) Members Online Today. Click the Manage Settings link here to customize the various options for this mod, then save the settings. Be sure to select which group(s) can view the list by holding down the Ctrl key and clicking on each group.