1. 只进行单位转换，保证实际长度一致.(When you just want to convert the Unit but keep the same length.)
a. Start->Program->nx 3.0->nx tools->Command Prompt
b. Cd path:nx3.0ugii
c. Ug_convert_part -in (-mm) path:partname.prt
2. 进行单位转换，保证数值一致，实际长度放大或缩小.(When you make a mistake unit, So you want to convert the Unit but hope keep the same parameter value. )
a. 启动 UG, 打开UG part 文件，进入Modeling.
b. Toolbox->Expression->export 产生 partname.exp 文件.
c. Start->Program->nx 3.0->nx tools->Command Prompt
d. Cd path:nx3.0ugii
e. Ug_convert_part -in (-mm) path:partname.prt
f. Close UG part 文件, 重新打开 UG part 文件。进入Modeling.
g. Toolbox->Expression->Import with option(Replace Existing)
