Hey Joanna,

I found this blurb on whfoods.org

Tips for Preparing Sunflower Seeds:

If you want to remove the shells from unshelled sunflower seeds, there are easier ways to remove the shell than by hand, which requires a lot of diligence and time. The quickest way to shell sunflower seeds is to grind them in a seed mill and then place them in cold water where the shells will float to the top and can be skimmed off with a slotted spoon.

While not as efficient, another alternative for those who don't have seed mills (which is probably the majority of us) is to put a small amount of seeds into the bowl of an electric mixer, pulsing the mixer on and off a few times for a few seconds each time, until the shells separate but not too many seeds are crushed. Then plunge the seeds into cold water as described above to separate them from the shells. However, shelled sunflower seeds are plentiful in the stores so there is no need to go through the trouble unless you have harvested them from your garden.

Hope that helps!