Clients using SP10 or higher can be auto-updated (though service desk official supports this feature after SP11). In order to enable this on server you have to use SP11.
Using it is quite simple. Open Administrator Console and on General Settings go to the tab [Remote Updater]. Check Service pack. Now when a client v 4.5 SP10 or higher attemts to connect to the server, it will get the client sp automatically.
In order to distribute a client Hot Fix automatically, check "Enabled" on Hotfix and locate the hotfix.jar file. If a client sp10 or higher connects to the server it will auto get the hotfix specified there.
Unpack the Service Pack and then look in the DOC directory. There should be a directory named itsm006537. Open the itsm006537..htm file and you should get the info that you are after. One word of warning. If you have the remote Updater enabled in a development environement and then migrate it to production using a database backup-restore then disable the remote updater and then re-enable it once the database is in the new environment other wise clients will get error messages.