You'll need a decent strap wrench and a small hammer, plenty of patience. Wrap the wrench around the sphere and tighten it. Try to turn it counterclockwise. If it won't shift, tap the sphere with the hammer, but don't hit it too hard. You could try some good old WD40 around the join, but I wouldn't hold out too much hope. It's all a question of leverage.
Sandman, December 2008
