Audi A6 avant leaking pano roof/ independent specialist needed

Hi All,

after some help.

I recently bought a A6 avant (C7) 63 plate.

lovely car except it suffers from the common issue of sunroof leaking into the foot wells on both sides. 
 

I have seen the thread about using captain tolleys creating crack cure to seal it which I have done as a temp measure.

I want to know if anyone has actually had the cassette changed, where they did it and what they got charged.

I can’t seem to get anyone to give me a figure, everyone will call me back then never does which tells me it’s a pain in the back side. 
 

If anyone knows a good independent around West Yorkshire that could do this I would like to know.

audi did send me a diagram to show me what would need to be changed (everything under section 1)

thanks in advance