I've been able to have a lot of seedlings to sprout in the past week and many (maybe 40%) of them were hull-bound (ie. the "seed cap" was stuck to the seedling).

I've realised that if you gently bend the hull forth and back, pulling it a bit upwards while doing so, it comes off quite easily, without damaging the seedling.  Of course the seed-leaves need have a manageable size before you try to do that (otherwise you may break it).

I´ve noticed that if you also sprinkle some water on hull, it softens and is little bit easier to remove.

I've read in other forums that you should always try to avoid removing the seed hull, but I didn't have any problems with the seedlings (around 10) from which I removed the hull by hand.

There were also some other techniques, such as cutting the tip of the hull so that the leaves could go through the seed and open the hull more easily.

Yup, sometimes it succeeds... but a bit too often it just doesn't. One tiniest mistake, and goodbye... :(