Please follow these steps:
1. Type DWGUNITS and press Enter.
2. The current drawing unit system is the number in Unit of length <X>
(1 Inches, 2 Feet, 3 Millimeters, 4 Centimeters, 5 Decimeters, 6 Meters).
3. Enter the desired option (number) to convert to and press Enter.
4. In Linear Display format, select the desired decimal precision and press Enter (i.e. 6 means 1,00000).
5. In Scale objects from other drawings upon insert? type Y and press Enter (optional).
6. In Match INSUINITS to drawing units? type Y and press Enter (optional).
7. In Scale objects in current drawing to reflect change in units type Y and press Enter (mandatory).
8. In Include objects in Paper Space? type Y and press Enter (optional).