My neighbors’ macademia nut trees are laden with more nuts than they can use so I googled and found this great Utube video:

http://www.youtube.com/watch?v=XNAtcbz1_N0

Here is the summary of what I learned from all the articles I googled:

1. Crack the green husks with a hammer if they are not already cracked. There should be a nice rich brown colored shell inside. Another video (below) suggests drying them first, then they crack open easily.
2. Dehydrate them so that the meat inside separates from the brown nut shell.
3. Crack them open, you can get a special macademia nut cracker

and here is another good video on growing macademia nut trees and harvesting:

http://www.youtube.com/watch?v=zlX67lh8wj