How to replace Cartridge on this bath tub faucet?

[kamabazi]

So I have tub faucet that is about 15 years old and leaking quite bad now when I pull it so water comes from the shower.
I need advice on how to take apart the thing and change the cartridge.
I did for my other bathroom but the faucet was quite different.
This one I cannot tell how to remove to get to the cartridge. also if anyone know what cartridge fits here.

This is a circular handle with hot and cold by turning side to side and made by Price Pfister. I searched their site but not able to find anything perhaps since it is such an old model.

Anyways I have attached a couple o pics, perhaps some of you can give me guidance or better yet point to soem published instructions for it.
https://docs.google.com/file/d/0B8exK7igwAVeRXMwVFYzb3B5bTg/edit?usp=sharing
https://docs.google.com/file/d/0B8exK7igwAVeUWs1VG40V3RWUUE/edit?usp=sharing
https://docs.google.com/file/d/0B8exK7igwAVeTkRYMVRSOWhaVnc/edit?usp=sharing

Thx!

 

[IFIXH20]

Looks like a Price Pfister Avante with round trim plate. The silver plate on the front of the handle should come off (pry off with a small screwdriver) to access a screw inside the handle to remove handle. Once handle is removed unscrew nut that holds trim plate in place to gain access to valve & cartridge.

 

[kamabazi]

Thanks, I will give it a shot by prying it with flathead screw driver.
I had tried using a wrench and twist the cover off but it did not budge. Kind of odd but it may be just snap in rather than twist on like I was thinking.

 

[kamabazi]

OK tried to use a flathead screw driver but no go. There is really no gap to put one. Even tried my very small laptop flat head screw driver and it will not even go.

So thinking it is screw in. Tried using a large pliers(diameter is 2.5") and held other part of the handle by hand. Twist quite a bit but it does not budge. Seems stuck.
Already put some WD40 overnight but seem there is no gap and it will not let it in.

Any ideas? Thinking of using hear blower to heat it up and then twist next but looking for ideas.

 

[IFIXH20]

Kamabazi, try removing (by unscrewing) the chrome plate with a pair of channelock pliers. Hold the handle so it will not move when trying to unscrew plate. There might be a rubber gasket behind plate making it a little harder to remove. Place a piece of rubber or something over plier teeth to prevent damage to chrome plate.

 

[kamabazi]

Finally was able to do it.
The small cover in the pic is screwed in and over the years got jammed. Had to spend well over an hour in it. Got one of the rubber strap wrench to hold the bronze piece in place and the using a wrench took it off after a lot of force. Thankfully nothing broke as I was afraid some pipe may go.
Pulling the cartridge was not easy task either as it was stuck but finally came out.
Finally done. Thx

 

[IFIXH20]

Good job Kamabazi