In a large plastic food bag (or bowl), combine lemon juice, oil, oregano, garlic, and pepper.
Trim and discard excess fat from chicken legs. Rinse chicken and place in bag (or bowl). Seal and turn bag to mix chicken with marinade (or mix in bowl and cover airtight). Let stand 10 to 20 minutes, turning occasionally. If making ahead, chill chicken in marinade up to 1 day.
Lift chicken from marinade and place pieces slightly apart on a rack in a 10- by 15-inch broiler pan; reserve marinade.
Broil about 6 inches from heat, turning as needed to brown evenly, until meat is no longer pink at bone (cut to test), 25 to 30 minutes total; up until the last 10 minutes, baste occasionally with the reserved marinade. Add salt to taste.