If you don't have a steamer, you can still steam crab legs using a large pot and a few simple steps. Here's a method you can try:
Fill a large pot with about 1-2 inches of water. The water level should be below the bottom of a colander or a heatproof bowl that you will use as a makeshift steamer.
Place the colander or heatproof bowl upside down inside the pot, ensuring it sits above the water level. Make sure the colander or bowl is stable and won't tip over.
Bring the water to a boil over medium-high heat.
Once the water is boiling, arrange the crab legs on top of the colander or inside the heatproof bowl, making sure they are not submerged in the water. You can bend or break the crab legs to fit them into the pot if needed.
Cover the pot with a lid, and reduce the heat to medium-low to maintain a gentle simmer.
Allow the crab legs to steam for about 6-8 minutes, or until they are heated through.
Carefully remove the lid, as steam will escape, and use tongs or oven mitts to take out the crab legs from the pot.
Now your crab legs should be steamed and ready to enjoy. Serve them with melted butter, lemon wedges, or your preferred dipping sauces.