First you need to till up the garden area.
Water the soil heavily as you want it wet at least 1 ft down.
Roll out your clear plastic, covering the entire area. Weighing it down using bricks or staking it so the wind doesn't grab it.
Leave it there for 4-6 weeks (warmer climates 4 weeks, cooler 6) checking every 2 weeks to make sure it is still damp.
Your soil temp should reach 114F. And although this process should not kill off the good organisms, it would still be a good idea to make yourself some compost tea to water the garden with.
To make sure you don't have to do it again, cover the garden after it has been depleted and retilled, in a heavy black tarp to keep weeds at bay until next spring.
I will be doing this today, and will add photos this afternoon.