Small drill bit, carefully enlarge the hole in the cap.
Screw in a small self-tapping metal screw and pull cap out w/ pliers.
They are not glued in....just press fit and they come out pretty easily.
For detailed instructions, go to the Tech Vault and follow Dinqua's Carb Jetting instructions. It's back a few pages but it's there.
You may want to remove the carbs and turn them upside down per the instructions if this is the first time you have worked on them.