I'm trying to updates Excel for Mac 2016 and Word for Mac 2016. Apparently when I go to help I should be able to see a 'Check for updates' menu option. However, I cannot see this menu option - see screenshot. how do I update Excel for Mac 2016 and Word for Mac 2016?
Don't know what is going on with your install of Office 2016 Mac but mine has that option under help.
If I launch Microsoft Autoupdate that way it shows me that the actual app is here:
You should be able to launch the Microsoft AutoUpdate.app manually from there.