Re: auxillary belt
stuffed as in no water pump, power steering, aircon and alternator, but it will not cause any damage, unlike the timing belt.
It is DIY able, just need a spanner on the end of the tensioner, release the tension and take it off. To put on, thread round the various pulleys and when you get to the tensioner, pop the spanner back on, tension it and thread the belt over, release and job done.
Most difficult bit is remembering the path it took, so best take a pic before you start.