Peeler crabs shelling them.Right you've got a peeler that is popping and in prime condition for a hook or to freeze for later on.

Next Remove the shell so it looks like this;

After this remove all the carpace,gill plates/covers,and most bits of shell

After this remove the lungs/gills if freezing doesn't really matter if your using the crab straight away when fishing.
The Lungs are located either side of where the side plates where removed;

Freeze in clingfilm/tin foil or lash onto your hook with elasticated cotton and thats it...
