Williams' senior technical duo Sam Michael and Jon Tomlinson are leaving the British team, while 'spygate' conspirator Mike Coughlan is joining as chief engineer.
We reported recently that technical director Michael, and chief aerodynamicist Tomlinson, were at the top of the hit list as Williams looks to restructure following its unprecedentedly-bad start to the 2011 season.
They will both leave the Oxfordshire based team at the end of the year, Williams said in a statement.
"They have recognised that the team's performance is not at the level that it needs to be and have resigned in order to give the team the opportunity to regroup and undertake the changes necessary to get back to the front of the grid," said team principal Sir Frank Williams.
"He left formula one in 2007 because of conduct which he acknowledges was wrong and which he profoundly regrets," said Williams, who said Tuesday's announcements were only the "first step" in the restructuring of his team.