Buying the service manual will pay for itself over time IMO, and much more info. than the Haynes. The dealerships around me charge $80 per hour for labor. So instead of paying 3 hours of labor, you could buy the service manuals instead and do it yourself. It will more than pay for itself overtime.
BTW, I just ordered one yesterday from Tweddle Litho Company 1-800-639-8841. $210 for the cd-rom wersion (cheapest I found). More info. can be found in your owners manual.