It says "Removing the carb can be quite a big job if the air box is removed first.". Actually that's the easy way to do it. I think this should say "Removing the carb can be quite a tricky job if the air box has not been removed first and you don't know the technique, but it can be done without damage to the inlet/outlet rubbers. Unscrew the forward clamp completely and retain the screw. Lever the carb rearwards from the cylinder head and out of the forward rubber, compressing the carb against the rear rubber intake and pushing it rearwards. Then pull it sideways out of the forward rubber and finally forwards and down out of the rear rubber."
You could also read that as saying that removing the carb is quite a big job if you use the method that involves taking the airbox off first. It's just semantics, but the campaign for plain English would be happy with a rewording
I agree that taking the airbox off is the easy way to do it as it avoids putting any strain on any of the vulnerable rubber boots and hoses, especially when they're old and hard.