Start by creating a map and attaching the MyDefinition.xml object class definition file and the source drawings.
To create a map that contains the object classes you defined
New
Drawing. Select the map2d.dwt template and click Open. 
Attach the MyDefinition.xml definition file.
Attach Source Drawings. 
Attach the drawings containing the classified objects.

Select all three drawing files.
You might see an alert as you work through the remainder of the tutorial. The alert warns that the association between queried objects in the current and attached drawings is not retained once the current drawing file is closed. This message reminds you to save back any changes you make to the original drawing file. You can safely ignore the alert.
To continue this tutorial, go to Exercise 2: Assign a coordinate system.