Turn off the air to the hatchery. Then if you use a flashlight you should be able to see them swim towards the light. The shells and unhatched eggs should rise to the surface.
My hatchery drains from the bottom so I just turn off the valve before it empties completely, leaving the shells and unhatched eggs behind. Then I strain the shrimp with a brine shrimp net and then put them in a container with some clean water. Then you can either pour them into your tanks or use a turkey baster to squirt them in.