Just lift the slides out of the carbs. Unscrew the top cap and they lift out. Careful not to whack the needles and make sure you align the slot in the slide (throttle tube) with the guide pin in the carb body..... when you tighten down the top cap, make very sure it goes on straight. Easy to cross thread.
P.S. mark them 1-4 to make sure they go back where they came from.