How do I change the position and orientation of a player's limbs in a script?

I was looking around on scriptinghelpers and found this in an answer:

local Left_Shoulder = Torso:WaitForChild("Left Shoulder")
Left_Shoulder.C0 = CFrame.new(-1.5,1,0)
Left_Shoulder.C1 = CFrame.Angles(math.rad(45),0,0)

And that rotates the arm just fine, but I want to change the position too. How do I do that?