Hi,
In Symantec Management Console you can click Manage > Computers menu item to open Computers view. There you may select a required computer (or search for it) in the All Computers list view, right click on it and from the opened context menu click 'Schedule task' menu item. In the opened 'New schedule' window click 'Select a job or Task' link. 'Select task' window opens where you may select 'Update client configuration' task by navigating to the following tree node: Jobs and Tasks > Samples > Notification Server > Update Client Configuration.
Optionally you can select any other task you'd like to be executed on the targeted computer using the way described above.