I found this simple solution worked for me. Find the Syncservicesagent app in your applications folder (the search function in Finder can easily do that). Click and grab the application and move it to your desktop. Once there, rename it to something like Syncservicesagent1. Then go back to Activity Monitor, locate Syncservicesagent and do a Force Quit. It will not restart this time because it can't find the app. Now you can do the upgrade. BTW, I left Syncservicesagent on my desktop in the renamed form and did not move it back to its original location in Applications. So far, my Office applications are working just fine without it. However, I do not use Outlook or any other Microsoft applications except Word, Excel and PPT. I plan to leave it permanently out of my apps - it's just wasting CPU for me.