if you take off you side cover , clutch side of course you'll see your clutches and basket ect. there will be a little screw in the middle of it all, it has a nut over it to keep it in place, if you loosen the nut you can either screw it out for less clutch play or in for more, in your case screw it out, start with half a turn at a time and after each time push your bike forward while in gear with the clutch engaged and you can see the the clutches spin and the bike will roll how it should when adjusted correctly, when your done tighten the screw make sure you get it tight enough that it won't come loose while riding good luck
ps if it is not clear enough do a search for your problem in this forum and you'll find plenty of topics on this.