Educate me on slides

I currently own (amongst others) a G43 with a standard, unmilled slide.

If I were to purchase a new, third party slide that's pre-cut for an optic (from, say Palmetto State Armory), does the slide come complete will all it's various parts like the striker, extractor pin, springs, etc.? Or do I need to move those parts from my factory slide to the new slide? And if so, how complicated is that?

Thanks