The SP1 release of Microsoft Office 2013 Click-to-Run for Office365 offers a new Update Now feature on the File | Accounts (backstage) page of each Office application:
This new feature allows users to check for and install updates for Office on demand. Under the hood, there is a new OfficeC2RClient.exe file that makes this possible.
Outside of this user interface, the OfficeC2RClient.exe can be run from an administrative command-prompt by constructing an appropriate command-line in the following format:
%Program Files%\Microsoft Office 15\ClientX86 | ClientX64\OfficeC2RClient.exe /update user variable1=value variable2=value … variableN=value
Where the variables are optional settings and based on the following table:
True | False (Default: False)
This specifies whether or not the user will see this dialog before automatically applying the updates:
This specifies whether the user will be given the option to cancel out of the update. However, if this variable is set to True, then the applications will be shut down immediately and the update will proceed.
True | False (Default: True)
This specifies whether the user will see a user interface during the update. Setting this to false will hide all update UI (including error UI that is encountered during the update scenario).
15.0.xxxx.xxxx (Default: Install the latest released build)
This specifies the version to which Office needs to be updated to. This can used to install a newer or an older version than what is presently installed.
A list of Click-to-Run version numbers is published at http://support.microsoft.com/gp/office-2013-click-to-run.