If you are travelling with a large tourist group, then you'll have nothing to worry about. Your group will likely travel by bus around the area, but you'll be one of those unfortunate ones who are stuck with little freedom of decision making! For independent travellers, arranging for private transportation is the only way to visit the tombs and temples in the Necropolis of Thebes. Fortunately, local taxis are very accustomed to this and will agree to stay with you all day as needed, though you will have to agree on the price in advance. Many taxis await travellers at the ferry stop in New Gurna, across the river from Luxor. Alternatively, you could ask your hotel to arrange for a car (which could be a reliable taxi driver they know).
The Valley is situated 2 kilometers to the North of the Hatshepsut Temple (about 10 kilometers from Luxor). It is possible to reach the valley by bus or by car. Parking and entrance in the valley are on the distance about a kilometer from the tombs.
This distance can be overcome on foot. However the heat does not allow to make it with pleasure. Therefore some car-wagons go between the central entrance and the place where survey of tombs begins. Travel is free-of-charge and takes several minutes.
You may watch my 2 min o2 sec VIDEO-Clip on my personal YouTube channel: Egypt Luxor the Road to the Valley of Kings 2007