Agreed with Wythors about getting the parts from Ford. Aftermarket PCV valves often dont fit real tight.
If you remove the grommet (which might feel like hard plastic instead of supple rubber), you can get to the screen easier. A magnet, long needlenose pliers or a hook are common tools used to yank the screen out.
The screen is often called a breather if you ask for it at the store/dealership.
Good luck.