I guess a dealer will probably charge an hour not matter what...
I doubt there are G310 specific DIY videos but this bike use the same system as many many bikes, so if you search for clutch replacement videos, I'm sure you can find something close enough.
You basically have 2 adjusters, one at the lever end, one down on the engine before it connects to clutch (just follow the cable and you'll find the adjuster). Making the adjuster loose on the lever side should be enough for you to pull out the cable tip that locks in the lever. Then with that released the other end of the cable should be easy to disengage as well. Installation is reversal of these steps. Make sure you note where the cable is routed before you remove it, because not following the same routing could cause the cable to be too tight (when you turn the handlebar for example).
Here's a video, for a dirt bike but the principles would be the same.
Out of curiosity, why do you need to change the cable ? You damaged it yourself? If not, try to have it replaced under warranty - should not have to change it that soon - unless you have many many miles on the bike already.