Cut a slit, length-wise, into the shell of each piece of crab.

Melt the butter in a large skillet over medium heat; cook the garlic in the butter until translucent; stir in the parsley, salt, and pepper. Continue to heat mixture until bubbling. Add the crab legs; toss to coat; allow to simmer in the butter mixture until completely heated, 5 to 6 minutes.

Recipe courtesy of allrecipes.com
https://www.allrecipes.com/recipe/155375/crab-legs...