1. First create any model in BRL-CAD.
2. Run command prompt in the directory where you saved your .g model.
3. Convert .g model to .obj model by typing following command in your command prompt:
   g-obj -o model_name.obj model_name.g object
4. Open FreeCAD, create new project, click File->Import, choose your model, small window will appear. Select Alias Mesh (Mesh).
5. We can also make our model more accurate. We can do this by coming back to console and typing this command: g-obj n 0.1 -o model2.obj model.g sph. This way we made model called model2.obj.
6. Now let's again import this model to FreeCAD, and our model is now more accurate and smooth.