It is important to note that deleting an element type also deletes the linked element types that are linked to it.
To delete an element types do the following:
|1.||On the Model tab of the ribbon select Modeling Options. The Modeling Options window opens.|
|2.||Select the element type that you would like to delete from the list. Note that all element types except the Measure and Top Element types can be deleted.|
|3.||Click the Delete button or press the Delete key on the keyboard.|
|4.||A confirmation dialog will appear. Click OK to delete the element or Cancel to cancel the deletion.|
More about Element Types.