3ds Max natively supports the import of formats from SolidWorks (.sldasm, .sldprt) if both these programs are installed on the same system. You can do that from the application Menu ► Import ► Select File To Import dialog ► Files Of Type drop-down list ► Choose SolidWorks files.
You can also find some dedicated 3D conversion programs, like Babel3D, that should be capable of sldasm to 3ds conversion.
Open SLDASM file Open 3DS fileAn online CAD conversion service
A commercial online CAD converter
A 3D CAD translation software