First clear the gun and remove the slide.
Then remove the slide cover plate
Remove the Firing Pin assembly
Remove the Extractor Depressor Plunger (EDP) Assembly
Press the Firing Pin Safety in and hold it while removing the Extractor
Now remove the Firing Pin Safety (FPS)
Ensure the little spring didn't end up sideways under the FPS.
You can use the old spring that you removed if the new one got crushed or bent out of shape from being incorrectly installed. If the spring is attached to the base of the FPS it was installed correctly.
Reinstall the FPS and then test it by pressing it in and allowing it to spring back out. It should have a fair amount of travel. Now if the FPS is functioning to your satisfaction press it in and hold it while installing the Extractor into it's cutout. The spring tension of the FPS will the Extractor in place.
Now let's assemble the EDP assembly and install that.
Place the rod and spring together (spring will only fit on one end).
Place the black bearing on top of the spring
Place the EDP into it's channel rod first so that the black bearing is sticking out the slide (next to where the slide coverplate will be)
Insert the FP assembly into it's channel
Re install the Slide Cover Plate.
Test the FPS by holding it in and forcably shaking the slide back and forth. You should hear the FP assembly sliding back and forth in it's channel.