There are instructions in the user manual on P 106-111.
There is a preload spanner in the tool kit to adjust the preload. It fits in the notches on the spring preload collar. The collar has what looks like a ramp with some steps in it. The steps locate on an oval shaped piece on the shock body. To make your life easier spray a little lubricant on the threads of the shock. Turn the collar to the next taller step. This puts more preload on the spring, essentially stiffening it.
The rebound adjuster for the shock is a small slotted adjustment at the very bottom of the shock where it connects to the linkage. Rebound refers to how quickly the shock will extend. More rebound damping will slow it down. Now that you have increased the springs tension, you will want to add more rebound damping. Use a flat blade screwdriver to turn it clockwise and slow down the rebound.
The fork is adjusted by turning the knobs on the top. The red one adjusts rebound damping and , and the white one adjusts compression damping. Compression damping is the amount of resistance to compression of the fork. I don’t want to overload you with information, but all of these adjusters only effect low speed compression and rebound. This refers to the speed at which the suspension is moving up or down and not necessarily bike speed. To put that in perspective imagine you are going 10 mph and hit a 6″ speed bump that is 3′ wide. The suspension moves much more slowly than if you hit a 6″ curb at 10 mph. The suspension has a separate circuit that is not externally adjustable to deal with high shock speed bumps. The low speed adjustments you will be making effect things like brake dive, dips in the road, etc.
hope that helped