Here are a few helpful guides if you decide to install windows on your own.
Replacement windows can be ordered with different framing options depending on how they are going to be installed. Windows that are going to be installed into a stucco home usually have what is called a flush-fin or stucco-flange. Windows that are for new construction will have a nail-fin. New windows can be built without a fin at all if the window is going into a brick or adobe wall, or any other construction with a deep pocket.
Click here for the step by step to install a window with a flush-fin or no fin application.
Click here for the step by step to install a window with a nail-fin.