The following are links to PDFs to step you through how to convert from various Plant Applications using iModel Connectors. There are different documents depending on whether you are converting for iTwin or for PlantSight.
iTwin Conversions
Converting-PDMS/E3D-for-iTwin.pdf
Converting-Smart-3D-for-iTwin.pdf
Converting-SmartPlant-PID-for-iTwin.pdf
SmartPlant-Instrumentation-Connector.pdf
PlantSight Conversions
Converting-PDMS/E3D-for-PlantSight.pdf
Converting-Smart-3D-for-PlantSight.pdf