So what's the trick with the main halyard lock? If I tie the halyard to the ring I can get the sail up but not down. If I tie the halyard to the shackle I can get the halyard down but not up. There must be a trick.
On the Cap we've always tied it to the top which makes it easy to lock and we did the same with the C2. The trick to getting it off is to:
1) Pull halyard while mast is pointing straight back, then hold the tension on it while rotating mast to one side.
2) Pull down on main while easing halyard tension and it will come down.
Depending on your angle to the wind you may need to try either side.