Are you talking about the orifices on number 16? There are four of them in total.
Yes those burner caps should remove from the top to give you access to the scres to remove them. Let me know how you make out. They could be stuck on there and need some elbow grease to remove them.
Those number 6's should pull right up. I do not believe that there are any screws holding them in place. Grab, twist, pull.
In the past, I have had to use a flat head screwdriver to get some leverage to break them free.
Let me now how you make out.