I have 25 year old Stanadyne (Moen) fixtures in my bath tub. I want to replace the pop up drain and the diverter (built into the tub spout. Fr the drain, when I remove the nob there is no screw to remove and there is no screw below the stopper. How do I remove the stopper? As for the spout, again there is no screw to release and the spout will rotate but not unscrew. I'm afraid to pull too hard. How do I get it off?