If I understand you right the shaft of the clamp will not spin in the base hostel. The first thing I would try would be to put some penetrating oil on the top of the hostel and let it sit overnight if it does not loosen up a bit try it again.
When you're dead you don't know you're dead. It's the same way when you're stupid.
Balance - 31.0 cm, Weight - 358 g, SW - 346 Kgcm^2