Price-pfister shower hot side two valve O-Ring replacement?

Hello- What is the correct lingo for what I need to fix a leaky shower faucet?

I called ACE hardware, and they tell me I need a rebuild kit???? This is NOT a SINGLE hot/cold valve. What this is...are two separate handles, a hot and cold. When I try to find DIY videos or written instructions, all I get are single-handed shower valves that handles both hot and cold in one valve. I think I have a two or three valve shower assembly...I only have hot and a cold, where is the third valve located? (I have been told I have three)

I know that the plastic handles in time, get stripped, and I will have to replace those, but when I removed the handle, and torqued down tightly the threaded end of the stem using pliers, I still get dripping out of the drain spout. I took the COLD side plastic handle, which was not internally stripped, and placed that on the hot side, closed it off the best I could, and yes, it still leaks, so I'm guessing it's the O-ring. (Fingers crossed)

The three pics shown is what I've done so far...removed plastic handle, unscrewed the trim, unscrewed the nut that holds that outer threaded plastic tube that hold the trim on, and now I see a brass tube with a bigger nut behind it. I've tried to counter clock wise unscrew this big nut, but I am afraid something either will break or become loose. Any ideas? The dripping is driving me crazy!

Thank you!

Remove the remaining nut...

You will need a faucet wrench set for sockets to grasp it.

Are you sure it is price pfister?

Thanks, and yes, my brother the plumber installed them when he re-piped the home. I asked him,he told me it was a PFister, but do you think he would come over to assist his older bro? He told me it's common sense,but I told him, if all plumbing repairs were common sense, then EVERYBODY would be a plumber! I honestly have never repaired anything at all in my lifetime. My scope of trade for many years was wallpapering,and painting,I even replaced a few toilets in my day, but as I recall, I've never dealt with shower valves before.

So IF,.... I can find this faucet wrench set to remove this arm,tube,whatever this thing is called, connected to the big nut, then I can replace the 0-ring?

In removing this nut.....Could I somehow loosen anything inside the wall that could later on damage the interior with water leakage? In other words, is this big nut removal easy to do? If I can't afford this special wrench set, would regular channel locks work? Or wrench set is better?

Someone told me I did not have to remove the plastic nipple (that threads onto the trim) Then said something about going through the inside with a special smaller tool to remove ONLY the 0-ring? Do you think they mean through the small stem, or through the inside of the now exposed bigger nut?

They are right.....Plumbers say..... "Your poop, is our bread and butter"!

You will need the water shut off before removing the remaining nut and you should have the valve in the open position.

Once you have it removed you should be able to pull it apart and replace whatever was leaking.

What was the leak by the way?

Hi and no leak yet!

I bought that wrench tool from home depot...$6.00. I opened the stem all the way,turned off the water to the house. removed the stem from the inside wall pipe. When I carefully removed this stem, i did not notice the 0-ring on the stem, but inside along the edge rim, so I preceded to unscrew the small Phillips screw holding down the flat washer, replaced it, and re-inserted the stem back into the walled pipe. I did not use plumbers grease or Teflon tape,but hope this will work. I shut off/closed this stem, went outside and slowly turned the water back on...THEN......and....and.....and.....one drip, one s-l-o-w drip...not the constant drip,drip,drip that was filling up a gallon of water in about an hours time before the repair.
Because of this one slow drippity drip, I went ahead and replaced the other (cold stem as well) now, no leak! Thanks to all who chimed in and helped me..much appreciated.

Next time it will be the replacing of both stems.