One day leaning on the armrest of my Herman Miller Aeron chair I managed to snap it off. Its served me for 15+ years and it was even second hand then, despite that I figured it was fixable. Getting the parts is ok if you are in the US but if you are UK based a bit trickier unless you know where to look for the bits. This shows you how, and you can fix your chair for a few pounds if you know where to look! This video enables you to fix your chair whilst avoiding "imperial entanglements" of the fact that those bits are harder to find in Metric Britain (even though Britain firmly seems to have both, you just need to know where to look) . This vid shows you all you need to know to fix this chair (not the newer versions mind you they look a bit different) that is the iconic Herman Miller Aeron B office chair.
If you used this video to fix your chair please share in the comments, this is why I do it. (The feeling of having helped someone)