How to turn a .stp file to 3D file
1 Answer

To turn a .stp file to another 3D format:
1) open ".stp" with supported softwares (e.g. Catia, Solidworks, ...) or online convertors
2) use "save as/export" to save the model to the supported formats (e.g. ".CATPart", ".SLPRT", ".stl", ...)
*advanced : to extract the model, you can extract surfaces using Catia--> Start-->Shape-->Generative Shape design then use the commands like Insert-->Operations-->Extract.
*if you want to print it, check the format required for your printer software & printer. Maybe the ".STL" format work for you.