Open AutoCAD. Open install.dwg that is located in the Install folder where you installed Design Master.
Type APPLOAD at the command line. Select dm-unloadFromAutoCAD.vlx and press the Load button. The press the Close button.
This will remove the Design Master menus from AutoCAD and remove the Design Master support paths.
Use the standard Windows Add or Remove Programs command in the Control Panel to remove the Design Master files from your computer.