How to extract the models of my saved sims?

Not sure if this goes here... But, I want to be able to get the actual models of my sims, and then be able to get them into a .fbx/.obj model, then rig them and then be able to pose them in a modeller. (like Blender)

Is this actually possible? I've seen someone manage to do it, but they're not telling ANYONE how to do it!