Ford invited thousands of employees to celebrate the re-opening of its Michigan Assembly Plant in Wayne, MI after an $850 million refurbishment.The plant is just now starting production of the all-new Ranger mid-size pickup, due to go on sale early next year, and will begin assembling an all-new Bronco sport utility vehicle in 2020.The plant opened in 1957 building station wagons, then produced the original Bronco for 30 years beginning in 1966.After an 8-year run building Ford Expeditions and Lincoln Navigators, the plant wrapped up production of the Focus earlier this year and underwent a major retooling in preparation for the Ranger.Ford is aiming to replace 75% of its North American entire vehicle lineup by 2020, with a renewed focus on trucks, SUVs and commercial vehicles.