Converting Units of an Entire Part
1. Open CMD in Windows.
2. Change the directory to C:\Program Files\UGS\NX 5.0\UGII or wherever your UGII folder is.
3a. To convert to inches from metric enter this into the command prompt:
ug_convert_part -in c:\user\part.prt
3b. To convert to metric from inches enter this into the command prompt:
ug_convert_part -mm c:\user\part.prt
Replace "c:\user\part.prt" with whatever the path to your part is, but apparently the path cannot be very long, or this conversion won't work.