1. In FEM-Design
No special model preparation in FEM-Design is necessary and all you have to do, is to save your model as a .struxml type. But you shall remember that not all the native FEM-Design elements and geometry is allowed in Revit.
2. In Revit
At the current version of the StruXML StruSoft Add-In, it is required that all the bar, floor, wall and foundation types that you wish to transfer from FEM-Design, existed in the specific Revit project prior to the import. So, before you import your model, make a list of all the element types used in your FEM-Design model and check if they exist in the Revit project. If not, load or create the specific families and types.
Here you can read more about the challenges when importing FEM-Design model to Revit.
When you installed the StruXML Revit Add-In, and created all the necessary families and types in Revit, you can proceed with the import procedure. Check out the following video tutorial to learn how to import a FEM-Design model to Revit. Detailed description of the import procedure can be also found in the User Manual.