If you're looking to import OBJ files into Autodesk Inventor 2013 for 3D modeling, you're in luck! Here's a step-by-step guide to help you get started:

1. Launch Inventor 2013: Open Autodesk Inventor 2013 on your computer to begin the import process.

2. Locate the 'File' Menu: Once the software is open, navigate to the 'File' menu at the top of the screen.

3. Choose 'Import': From the 'File' menu, select the 'Import' option to initiate the import process.

4. Select OBJ File: A dialog box will pop up, prompting you to select the file you want to import. Navigate to the location of your OBJ file, select it, and click 'Open' to proceed.

5. Adjust Import Settings: After selecting the OBJ file, you may be presented with options to adjust the import settings, such as scale and units. Make any necessary adjustments and click 'OK' to continue.

6. Review and Edit: Once the OBJ file is imported, you can review and edit it within Autodesk Inventor 2013. Use the software's tools and features to modify the 3D model as needed.

7. Save the Project: After making any desired changes to the imported OBJ file, be sure to save your project to retain the modifications.

And that's it! By following these steps, you can successfully import OBJ files into Autodesk Inventor 2013 for 3D modeling. Whether you're working on a design project or simply exploring 3D modeling, this process will allow you to incorporate OBJ files seamlessly into your workflow. Happy modeling!