Adamantine golems has to be hit with a +2 or better BLUNT weapons, and it will only deal the + part of your weapon, say you have the Flails of Ages +3, then if you are lucky, you do three or less damage to it. You can't inflict the Iron/Ada golems with any elements, or magic since they're immune to all magic, fire/acid/eletrity/cold. etc.
It became easy to me since i had the Sling of Everd +5, i equiped it to Jaheria and she flicked the hell outa those golems, you don't have to get the Bonus or Collector's edition CDs to get Joluv and Diedre, following down the topics, you should find a post by me, including a link to the sites where you need to download the 2k joluv, deidre activation file as they're already included in your original BGII CDs.
Hope this has been helpful