Instructions
Travel to Khuul in the northwest extremity of the island Morrowind.
Speak with the dockworker in the northwest part of town. He'll offer to take you to Solsthiem. The only werewolves in the game live in Solsthiem. Accept his offer. You'll arrive in Fort Frostmouth, the gateway to the island Solsthiem.
Head west to the General Quarters. Go up the spiral staircase and enter the office. Speak with Captain Falx Carius. He'll send you on a series of quests introducing you to Solsthiem and the lycanthrope menace.
Proceed through the missions until you arrive in the remote village of Skaal. Speak with the shaman Korst Wind-Eye to begin a new series of quests. Follow these quests until you've finished the fifth Solsthiem mission, "Prove Your Strength." The following night a pack of werewolves will attack Skaal.
Defeat the werewolves. No matter how the fight goes, you'll contract lycanthropy. One of the guards will give you a potion of Cure Common Disease. If you take the potion within two days, you won't become a werewolf. If you wait longer than that, you'll have a strange dream, after which you will become a werewolf.