I tried all the solutions above, and the many others that are posted on various other forums (involving shift keys, activity monitor, dragging and dropping apps, renaming etc). None of them worked. SyncServicesAgent and the Daemon App would reactivate evcery single time, within seconds.
What worked for me was to start the update installation and get to the point where it require syncservices etc to be closed. At this point, i DISCONNECTED FROM THE INTERNET. (I also quit syncservices and the database daemon in Activity Monitor but I don't know if that step was necessary). Then I went back ot the update installation, clicked continue and it all went fine.
So the answer seems to be: go offline.
Good luck