Iterate through a Collection Object
Collection Objects
Understand Properties and Methods
To delete a specific dimension style, use the Delete method found on the member object. For example, the following code deletes the layer ABC:
Dim ABCLayer as AcadLayer
Set ABCLayer = ThisDrawing.Layers.Item("ABC")
ABCLayer.Delete
Once an object has been deleted, you must never attempt to access the object again later in the program.