How to modifity the scale of the drawing in a model space?

I believe your query is more relevant to using AutoCAD. I am more versed in3D CAD packages like SolidWorks (although AutoCAD has3D extensions now), and as you would know model and drawing files can be transferred within different software with proper file extensions. In Solidworks, the scales can be modified directly from the side menu options (models can also be scaled up or down), after which it can be exported to AutoCAD. This is what I would have done. Not sure if it helped, just felt like sharing. Cheers.

by  writing sc in command bar then select obgect then  entring sc referaance