Loosen the four allen head bolts on the carrier, put a screwdriver through the sprocket and into the hole on the carrier (left side) and push/pull the quad until the right amount of tension is on it! I always go by the width if my index finger and middle finger (about a inch) when it comes to the right amount of slack you need. And yes think of that last sentence like your rounding 3rd base.
Just finished adjusting mine, another good point is, after your done put a jack underneath the rear axle and lift it up until the rear tires are off the ground. Start quad and put it into gear, if the chain is tracking right it will cycle smoothly, if the chain is to loose it will jump around on top of the swing arm, you'll know if its to tight just by feel.