This video explains the use of the "XIN Extractor" tool to create Feature Definitions, Feature Symbologies, and Element Templates from the Styles and Named Symbologies in an XIN.
The XIN Extractor can currently be downloaded HERE, and is currently scheduled to be added to the Migration Utilities folder in the Q1 2019 release of OpenRoads Designer.(https://communities.bentley.com/products/road___site_design/m/road_and_site_design_gallery/273469)
This should ONLY be used for ORD 2018 Release 4 (10.06.00.038) or higher.
Click the video below to play it. To view in fullscreen mode, first click the YouTube link at the bottom of the video to launch the video on the YouTube site. Then, click the fullscreen button (rightmost button at bottom of video).