To Import Template, Custom Tool, and Custom Menu Data from an XML File

Do one of the following:

In the Element Templates dialog ( Drawing > Home > Attributes > Element Template > Manage ), select File > Import > From XML File.

or
In the Customize dialog ( File > Settings > Configuration > Customize ), select File > Import > From XML File.

The Import XML Data from File dialog opens.
(Optional) Click the Browse icon to navigate to a different folder and select the XML file you want to import.
Select the data types to import.
Click OK.
The dialog closes. The selected data types in the selected file are added to the open DGN file.