If you dead-set on cleaning the whole of your carpet, you might want to take all of the items and furniture out and leave the carpet's surface completely empty. Start off by vacuuming the bigger pieces of dirt and dust debris and then gently apply the shampoo cleaning solution. This process usually requires a lot of water and it will make the carpet wet. In cases like this it would be helpful if you have had a carpet shampooer, but it is also doable without one. Start shampooing from the very far angles and build your way out of the room. Do not forget to leave the windows and doors open for the carpet to ventilate and dry out faster preventing mold, or the AC on in case opening windows isn't optional or less practical.