Replace three-handle shower diverter stem

This piece is made of plasic and broke off at the 90* neck angle. (at least it is stuck on shower mode which, if it had to break, is what I would prefer.) I have ID'd the part # but have a couple of quesitons about replacing it. First, how difficult is this for the average joe? I have a diagram...

I have an older house, with the hot, cold knobs and middle diverter. I have changed both the hot and cold sides with no problem. I have taken the packing screw, cap, the small nutt, the larger nutt, the screw on cover that conceals the stem, now I only have the stem left but it will not come out....

The house is well over 25 years of age and I have replaced both hot and cold water valves and tub faucet without removal of bath and shower stall tiles - still look good. Purchased a diverter stem (Galtmaster tub and shower models - 1963 to 65). With the old diverter I would turn clockwise to have...

I Already Change The Diverter Stem On My Bathroom Shower. I Installed A New One (sayco). It Works Ok, Except When I Rotote It To Change And Send Water Only On Top Shower, Because It Send Also Water To The Bottom Shower (both ways). Do It Have Any Particular Way To Install It? Do I need to...

I am trying to replace a shower diverter stem. I took the old one off and screwed in the new one. When it's tightened all the way, there is no water flow. As I loosen it, the water begins to flow and I am also able to turn on the shower. But, that's no good because if it's too loose, it will fall...