Silverzx's White 205 1.9 DT XUD

[powerandtorque]

Make sure that the tank is as close to empty as possible (fuel light on solid as a minimum) as you need to tilt it backwards to remove it and you will spill fuel everywhere unless it's nearly empty - not to mention that it's heavy and even more unwieldy when there's a fair amount of fuel in it.

Paul's otherwise covered it fairly well - there's two breathers on the top of the tank (or at least, there is on injection tanks) and also you'll need to remove or lower the exhaust and handbrake cables.