LeBron James and the Cleveland Cavaliers may need a Herculean effort to upset the Golden State Warriors in the NBA Finals but the game's most prolific playoff scorer said he has beaten similar teams before. James acknowledged that toppling a Warriors team boasting two-time reigning league MVP Stephen Curry, four-times scoring champion Kevin Durant, defensive specialist Draymond Green and sweet-shooting Klay Thompson will be among the toughest tasks of his career.