JK Brickworks is behind many amazing LEGO sculptures. His Sisyphus kinetic LEGO sculpture went viral a while ago. As it turns out, someone has made a BB-8 kinetic sculpture inspired by that. As you can see in this video, the robot simply doesn’t feel like moving, so it is being pushed.
The instructions for this particular version are not available but you can always refer to the original work to learn how to build your own cool LEGO sculptures.