Cracking it open like a nut won't work, the skull is made up of several bones that are fused and the way they'll split will destroy the brain and make it challenging to recover enough of it to be meaningfully used. Best bet is to duplicate the ban saw cut shown in the YouTube video with a hacksaw with a coarse-toothed blade, and recover the halves of the brain after prying the skull open.
I've also heard of people cutting off the soft tissue of a grazing animal's nose and forcing a hose into it, then turning the hose on to force the brain out the opening where the spinal cord enters the back of the skull. These people weren't interested in eating the brain, just interested in getting it with the least amount of work possible (to brain-tan animal hides), so I don't know if this will be a useful way to get the brain out and keep it clean and whole enough to be edible. I imagine it would also make quite a mess, so would have to be done outdoors or in a room that was easy to clean afterwards.
