Using fist size (or larger) stones, build a rectangular firepit about the height of a basketball, wide enough to put your roasting pan inside sideways, and long enough to access and continuously build the fire up
Find 2 large flat stones roughly the same size (about the thickness of a baseball that is large enough to cover the back half of your firepit)
Place 1 of the large flat stones over the backside of your fire pit
Using fist size (or larger) stones, build up the sides and back of your oven, on top of the flat stone you've just placed (high enough and wide enough to place your roasting pan and turkey inside)
Place the remaining large flat stone on the top of the walls of the oven you've just created
Find a large flat stone to use for the door of your oven, large enough to cover the front opening of your oven
Gather small sticks, and start a small fire underneath the oven, using your matches and newspaper
Gather a large pile of large sticks and pile these near your fire (you're going to need them to keep the oven hot for the next several hours)
Using the large sticks, build up the fire to get your oven nice and hot while you prepare the Turkey