It is under the intake manifold, you might want to have a new set of intake manifold gaskets when you take out the 8 bolts, etc, etc. that give you access.
Disconnect battery, drain out antifreeze, remove and mark wires that will be in the way. Why do you think it is the knock sensor? Code? Haynes has a excellent 90-99 legacy repair manual. There are probably tons of them at Bookfinder.com.