Changing throttle cables without removing carbs...

[unfazed]

The secret to removing the carbs is when you push the airbox back full move the exup vavle cables out of the way on the right side and tighten the bolts holding the air box in place to keep it in that position.You wont have to remove them completely but you do need to dismount and take them half way out the left side.
I honestly do not see any possible way of doing it with the carbs in situ.