I need some info on a 2006 Subaru Lagacy 2.5L 4 cyl Turbo 70,000 miles. Bought from Carmax and previous owner had service records. Dealer wants $600 to change the oil, brake fluid, air filter and spark plugs and change collant. I can do most if not all of this. How hard is it to change the spark plugs and what kind of collant should I use? I will be using synthetic oil, most likely M1 5w-30w (when i talked to the dealer they said dino oil would be fine eventhough Subaru service bulletin now says synthetic for all turbo engines) Thanks for any and all info! Robert