replacing the timming belt difficulty

It depends on your mechanical skills, available tools and service manual. For a trained tech -with all the tools required- takes about 4 hours (the belt only) with all the timing components and water pump - about 6 hrs. You can find great repair manuals with step-by-step instructions, diagrams, parts locations and other important information here: http://bit.ly/mitchell_repair_manuals_online Or here: http://bit.ly/AllData_Repair_Manuals_Online Zee