Opening OBJ files in Blender is a simple process that allows you to work with 3D models from a variety of sources. To start, open Blender and go to File > Import > Wavefront (.obj) to load the OBJ file into your project. You can then manipulate the model using Blender's powerful tools and features. Once you have made your desired changes, you can export the model back to an OBJ file by going to File > Export > Wavefront (.obj). This makes it easy to collaborate with others and work with OBJ files across different programs. By following these steps, you can seamlessly integrate OBJ files into your 3D modeling and rendering workflow in Blender.