As previously noted, there is no free play adjustment, he has a hydraulic clutch.
Before assuming your clutch is shot, do a quick fluid level check. Make absolutely certain the fluid level is not above the maximum fill line with the master cylinder level (turn the bars to the right until the top of the M/C is as level as possible). Protect any painted parts before you pull the cover so if the level is too high and some spills out you won't ruin your paint.
The fluid level in the master cylinder reservoir tends to increase over time as the plates wear, which is opposite of how a brake system works. Rather than go into the details of why that is, just trust me, I know what I'm talking about. When the fluid level gets too high, the actuator piston cannot completely retract and the clutch doesn't fully engage, thus the slipping. While this may not be your problem, it is a very easy check and fix if it is the problem. Always check the simple stuff first.
Jerry