For all you mechanics out there, how hard is it to change the Idler and Pitman arm on a 2006 yukon Denali? I have mechanical ability (aircraft mechanic) but I really don't know a lot about truck so this would be my first time at doing this. Also I was quoted at a shop for the parts and they listed Idler arm and Idler arm with bracket???????? Isn't there just on Idler arm......