There is a notch between the two parts of the WP. on the top of the WP, that is large enough for a large screwdriver blade to fit in. Just put a screwdriver in and twist. Unless you hammer it in you won't come near the sealing faces.
Don't hit the thing with a hammer! When all the bolts are removed the whole WP assy is loose, so hitting the front of it won't break the seal from the main housing.
