Place the goggles on your eyes, the headphones over your ears and the work gloves on your hands. Place a respirator over your mouth to protect your lungs from airborne stone dust and particles.
Turn on the saw.
Place your foot on the stone beside the flagstone you're cutting off from the concrete. This helps you steady yourself.
Bring the saw down directly on the flagstone. Gently roll it forward across the flagstone to create a line. Then gently lift the saw up. Now go back to your original starting point on the flagstone. Go over the line you created, this time pressing the saw gently down into the stone so the saw reaches the bottom. Lift up the saw gently without pulling it out of the stone. Now roll the saw forward and press down to the bottom again. Continue lifting up the saw and pressing it to the bottom until you reach the end of the line and the flagstone is fully detached from the concrete. Keep an eye on your foot. You don't want it placed too close to the moving saw. You may need to walk with the saw, depending on how large your flagstone is.