To remove the Outlook Sync utility, you have two options.
Open the OutlookSyncSetup.msi file you had originally downloaded. This time, it will prompt you as follows:
Click the radio button next to "Remove WebMail Sync" and click Finish.
Alternatively, if you are unable to locate the file, then return to the Tools>Options menu in Outlook and select the Other tab. In the Other tab, click Advanced Options, then Add-in Manager. Now unselect the checkbox next to Outlook Sync and click OK. Restart Outlook.