Open one of your saved games with your best character, make sure you have best eq and lots of potions, and use the following sequence to enter level warp during play:

hold left trigger all the way (middle finger), hold right trigger all the
way (use middle finger), hold Y (right index finger), hold A (right thumb),
L on left analog stick (index finger), press START (thumb).

After chest menu comes up, warp to the Gauntlet. Beat the Gauntlet and save the game with your character. You will then open up Extreme difficulty as an option. If you want to play Drizzt, start up the gauntlet with him, and level warp him to the
tavern or town.