after you knockdown a magic golem how do you finally kill him

There are tons of books scattered all throughout the game. Most of these are history books, like "History of Dambrath," "History of the North," "History of Durpar and Var," etc, that do not contain any information about how to defeat enemies or solve quests, they merely provide background for greater game immersion. But many other books exist in the game too--they usually look different from the history books, and it is usually in your best interests to read them at least once. One book in particular is called "Elminster's Ecologies," and can be found in many Throne of Bhaal areas. I suggest you go find a copy.

Yes Six is correct there are certain types of weapons that can only be used to kill a magic golem. Read some of the Elminster book that you find and they will give you a clue as to what type of weapon to use.

Elminster's Ecologies will come in handy more than once. There are many copies scattered in ToB. IIRC, the first levels of Watchers' Keep contain several.

i have a copy but in there he said there is no way for this golem to be hit by magic or enchanted weapon. i killed him with my fighter's fists. but like trolls he is lying on "near death". but maybe the answer is in this book. he also writes that he knows that only non-magical weapons can hit this creaure

Well maybe you should buy a non enchanted Longsword, or axe or arrows. Made of regular unenchanted iron. Maybe that would work.

<span style="color: lightblue">Basic game oddity and non-sensicalness: you cannot kill anything with your fists. Ever. No matter how much damage you do, and how many times you punch them, they will always somehow manage to be alive (just), but asleep. This applies to all classes except for Monks.

Oddly enough, you should always seem to "find" unenchanted weapons before you fight a Magic Golem. It's usually a nice warning.

Do you have Jahiera in your party? Sword Spider form takes out magic golems like nothing else.

Can Jaheira do sword spider transform? I thought that was for one of the specialist druids only...avenger druid isn't it?

My Jaheira can only turn into bears (unless the sword spider transform looks like a bear...)

I'm sorry, I was confusing having Jahiera with my solo avenger game... Forgive me, you're quite correct.

Jahiera can, however, use a shapeshift and GWW to dice those golems.