I can help you change one and then copy it, though there ought to be a way to
do it all at once for the same type of control.
Open the template. Select an empty content control that you want to edit.
Turn on the Developer mode (It's on the developer tab. If you don't see it,
go to Word options and put a check mark in the the box before "Show Developer
tab in ribbon". ) Then click Properties. Change the locale from English
(US) to English (UK). Then set your preference for how the date will display.
OK out of the content control properties dialog.
Copy the edited control to the clipboard. Select the other, like content
controls and paste. Make sure you are out of the developer mode. Check to
make sure the developer mode is off. Save the template.
Pam