price pfister 3 piece shower stem

Hey guys, so i recently purchased my first home and after redoing some of the bathroom tile i noticed all 3 shower handles in my shower were lose the screw that screws the handle to the top of the stem was rusted and rotted in all 3. When i tried to unscrew them all 3 screws snapped off inside the top of the stems. After doing some research and going to the local plumbing supply house i was able to order the 2 new hot and cold stems (part # 910-030) theyre the ceramic ones and a new diverter valve. I want to replace the old trim kit can anyone tell me what specific kit fits these stems. Also do I need to remove and replace the valve seat for the diverter? And is there a specific way each hot/cold ceramic valve needs to be installed, as well as the diverter?
Sorry if these questions are simple. I searched google repeatedly and got nothing