Instructions
Equip your most powerful weapons. Greater Wolfweres can only be hurt by magical weapons with a +3 or higher enchantment. The silver dagger "Werebane" can also cause damage to the Greater Wolfweres, so give it to someone skilled in small weapon use.
Send in your tanks first. This is basic tactics; Greater Wolfweres can take a lot of damage and will dish out as much or more than they take. Send in your strongest fighters to stand toe-to-toe with them and keep your weaker party members back out of the fray.
Buff out your party. Clerics and Wizards should cast as many stat and defense buff spells as they have access to. Cast spells like "Strength" or "Haste" on your front-line fighters to give them a greater edge over their opponents.
Use "Magic Missile," one of the few spells in your wizard's arsenal that can get past the Wolfwere's invulnerability to weapons. Spam the spell as much as possible to cause heavy damage to the monster.
Keep everyone healthy. Make sure you have your cleric standing by to cast her healing spells, and make sure your fighters have a liberal amount of healing potions on their persons at all times. Monitor your party's health closely to make sure no one drops dead in the middle of the fight.