Simplify the following text for a Grade 9 native English-speaking person.
Original: Of Brawn 's 2009 drivers , Jenson Button signed for McLaren , whilst Rubens Barrichello moved to the Williams team for 2010 , resulting in Mercedes selecting a new driver line-up of Michael Schumacher and Nico Rosberg .
Simplified: Brawn 's former drivers Jenson Button joined McLaren , and Rubens Barrichello joined Williams team for 2010 .