To Publish a DgnDb i-model

Select File > Publish i-model.
The Publish i-model(s) dialog opens.
Check Create a single package.
(Optional) Click the button next to Embed Documents to select documents.
Check Create an i-model (.imodel) file.
Click Publish. The Bentley DgnDb i-model Importer creates an .imodel file.
Note: The Bentley DgnDb i-model Importer does not process external i-model references. Discoverable non-design files attached to graphical elements with manual design links are embedded into the .imodel file.