I am not sure if you're asking for 'how to adjust clutch cable', or 'how to remove and install new clutch cable".
Removing the cable is straightforward, take off the shift pedal, take off the sprocket cover on the engine (maybe remove exhaust based on how it is routed for you.. as well as maybe removing the foot peg as well). The clutch cable and the side cover will come off as an entire assembly, be careful when taking the cover off because s small ball bearing potentially could fall out of the mechanism.
On the inside of the cover, you will see the clutch actuator mechanism (don't remember exactly what it is called), with your finger you can make this mechanism move as if the clutch handle was being pulled.
Do this, and the clutch cable end can be removed from its little slot thing in the mechanism.
From there, the cable can be pulled from the sprocket cover hole.
To remove at the handle:
Loosen the adjuster screw all the way off. With the slack you have in the cable, you should be able to pull it from its slot in the handle.
( I hope this was all clear enough, kinda hard to explain without pictures)
Reverse it all to install new cable.
To adjust the cable, see page 22 of FSM. Here's the link.
https://drive.google.com/file/d/0B8RLEMngUB63bjlyMHdFbVkydHM/edit