Raze's advice to kill Raze is solid, this way he's relatively easy.

First, drink potions that increase your damage resistance and damage output (int for casters, str for warriors, ...). Then run to the levers and pull both, then use as much force on Raze as you can. If you have a decently statted and equipped char and unload all your damage-dealing (spells, weapons, ...), you should get him down quickly enough.

If that does not work, you might need to come back later with more levels. You can try to reduce the game's difficulty for this fight. I found that Raze is one of the toughest fights in the game unless you are VERY dexterous (you as player) to pull of several rounds of pulling levers or have a char that can really ditch out some serious damage so one round is enough to kill him.