As a former chef in a few seafood restaurants, here’s the answer: The lobsters were packed and shipped in seaweed, weren’t they? THE BEST way to store the lobsters is in the same container they came in - with the seaweed. Put the container on the bottom shelf of your refrigerator. This is the coldest part of the fridge.
How to prepare them: Use tongs to take them out of the container with the seaweed and to put them into boiling water. (yes, they must be alive at the time you‘re ready for them.). After boiling the live lobsters
[Not sure how long or what to put in the water with the lobster? Please consult your cookbook or go online and get some mouth-watering recipes], split it from the head to the tail so you have 2 mirrored halves. Remove and throw away that small, oval-shaped, tannish, brownish colored 1/2 sac behind the eye on each 1/2.
Remove the tamale [that green membrane] and the other edible parts of the body's interior.
Break off the small legs on either side of the body.
DO NOT USE OR EAT "the devil fingers" - those spongy-looking, soft, greyish/tannish, feather-looking membranes attached to the shell's body's side.
Detach the claws and crack them with nutcrackers or a hammer.
Remove the meat from the tail.
What you have left are approximately 2 piles: the first containing what you paid for: claws/claw meat, tail meat, legs and edible interior body.
The second is what you also paid for, but what you probably don't want - unless you are going to make lobster stew or bisque or another lobster-based dish. This gets tossed. DO NOT put any lobster shells or inedible parts in your garbage disposal.
Need some "drawn butter"? Put a pot of water on the stove.
Bring it to a simmer.
Unwrap and put 2 sticks of butter in a smaller pot.
Put the smaller pot inside the larger pot with the simmering water.
Go ahead, let go of the smaller pot with the butter. The pot with the butter will float.
Let the butter melt.
The butter's butterfat will naturally come to the top.
The butter's milk solids and water will sink to the bottom.
You can pour the melted butter over the cooked lobster OR serve it on the side. You do not want to use the liquid which sank to the bottom of the smaller pot.. Its salty and its water. You really can't do anything with that salty water. other than letting it cool, putting it in a plastic bag, sealing the bag, freezing it and throwing it out on trash day.
Enjoy ALL that great-tasting edible lobster. OR you can make the lobster[s] part of a New England-type clam bake with other seafood, potatoes and veggies - like corn-on-the-cob - if you like.
When you asked your question, you did a great job - not only for yourself, but for every other person reading my answer.
I wish you well!
Graduate of the Culinary Institute of America ["The C.I.A."], New Haven, CT campus.
Over 26 years in the food & beverage business. Did EVERY job and held EVERY position in the business.