This technique works for East coast blue crabs, where you don’t have paralytic shellfish poisoning. For Dungeness crabs, we consider it safer to kill the crabs first and clean them, removing all the organs before you boil them, so the meat doesn’t get contaminated.
Boil water. Add live crabs. Cook 7 minutes.
Remove the following parts, in order:
1. Claws (keep)
2. Front legs (toss)
3. Back/bottom panel
4. Top of shell
8. The part near the back (if still attached at this point)
This would make more sense if I could find the diagram I sketched. Maybe I’ll find it someday, or I’ll take some photos.