Sorry, I did not pay attention that you are speaking about LT version.
Looks like there is no such menu item in LT version, but here is the help topic:

http://docs.autodesk.com/ACDLTM/2013/ENU/filesACGMacLT/GUID-A37DAD86-971E-4E5E-8D9A-DF03DC315336.htm...

You need to edit acadlt.pgp file, which is inside
~Library/Application Support/Autodesk/Roaming/AutoCAD LT 2013/<version>/<language>/Support
folder.
The Library folder I mentioned above is inside your Home folder, but nit the Library folder in the root of Mac HD.