Sometimes its the simple things..........loosen the handlebar clamp and move the bars to the left. Please put heavy padding on the tank so you dont inadvertantly damage the gas tank
That won't work well enough to remove the cable barrel ends from the throttle grip. You can leave the bar clamps in place that will not loosen the cable within the shroud. Then the first thing to do is turn your cable adjuster (nearest the switch housing w/locknut) all the way in. That will release the tension on the cable itself. Then remove that barrel first. If that's not enough you'll have to do the same thing with the adjuster (double nutted one) at the carb bank. That will definitely give you the slack you need.
Reverse the order when you readjust the cable. 1st set the switch housing adjuster to mid point then (2nd) adjust the one at the carbs to your liking. Final (3rd) adjustment (fine-tune) is the back at the switch housing adjuster.
Careful not to kink a cable especially near the barrel ends.