In order to change the default program a dwg file will open with, navigate to your system settings and select Apps and then select default apps:

Once in the default apps, you will want to enter the file format (dwg) into the search bar:

Your current default will appear as HyDraw Application. If you select the icon on the right, you can change the default application.
Some trial and error may need to be done depending on how many versions of HyDraw CAD are installed. The most recent version is typically towards the top. Once you have selected another option, select OK:
