drop the pan on the tranny and its right there, a big plastic thing. it just slides out, then you need to get the seal out of the pump with a screw driver or something. just don't damage the pump. then just slide a new filter up in there with the seal on the filter.
i would replace the filter if you are changing the fluid. if it gets cloged, it can't pump any fluid and its not moving. it may even burn it up because not enough pressure to the clutches and lets them slip.