Fitting a new cowl (Corgi registered?)

[J]

Hi,

After much investigation, and walking around our estate to see what other people have done, I've decided that in order to solve our problem of a down-draught via the chimney flue into our living room on windy days, I'd get a rotating chimney cowl like one of these:

chimney/flue is not far from the gutter protruding from the roof and takes the form of a galvanised metal pipe, about a metre in length. The house was built in 2000.

1. Is it easy to fit a new cowl in place of the not very good one there at the moment?
2. Do you need to be corgi registered in order to fit one?

3.And, has anyone got any recommendations as to a good make, I.E. with good quality bearings so the noise doesn't rumble through the house?

I'm not going to have a go at it myself as I haven't the balls to mess around at the top of a set of ladders, so I was going to try and find someone to do it cash as I doubt it'd take long to fit but wanted some advice.

Thanks,

Jon