EXPORT
From Visual studio command prompt, issue the following command to export your work item type.
C:\>witexport /f "c:\BugWIT.xml" /t myservername /p mytfsprojectname /n "Bug" /exportgloballists
Work item type export complete.
IMPORT - Validation
First validate the xml file, using the validate switch
C:\>witimport /f c:\BugWIT.xml /t myservername /p mynewtfsprojectname /v
Work item type validation complete.
IMPORT
Now import the work item type
C:\>witimport /f c:\BugWIT.xml /t myservername /p mynewtfsprojectname