It's just a matter of copying the two font files from the machine with Office 2013 and installing them on the machines with Office 2010.
On the Office 2013 machine, use Windows Explorer to open the folder C:\Windows\Fonts\Calibri.
Copy the Calibri Light file and the Calibri Light Italic file to a USB memory stick, a network folder, or some other transfer medium. (Windows Explorer does its best to hide the actual file names, which are CalibriL.ttf and CalibriLI.ttf.)
On the Office 2010 machines, right-click one of the files and click Install. Repeat for the other file.
Once the fonts are installed, they'll be available in all programs that use fonts.
