How do you convert a f3d extension file to a step or iges file to make it usable with solidworks
You'll need to open the file in Fusion 360 and export the file in the desired format.
This link suggests that Fusion 360 exports a wide number of file formats.
Iges, Step, parasolid, and acis can be imported by SolidWorks. I'd start with parasolid, then try step, acis, and iges if you run into trouble.