2004 Cayenne Turbo-noisy interior fan blower

[Walter Sobchak]

My car intermittently makes some really nasty rattling sounds from the blower motor, if you turn the fan off then on again it goes away but usually starts again as soon as you go over a slight bump or oddly turn left either, has this happened to anyone else?.
I’m giessing it probably needs a new blower motor, are they hard to do?.