knock sensor replacement

Have a check engine light for the knock sensor, so I bought one to replace it. The Haynes repair manual isnt real descriptive on the location of the sensor, it says it's on the back of the engine block. So, anyone know where in particular it is? Thanks
96 200sx se-r
sr20de 2.0L

just like it says. it should be somewhere in the middle of the block, usually somewhat near the top(headgasket area). its the only thing that sticks into the back of your block with a plug and harness.