Who to call to replace a velux

[IrisRoseLilyBriar]

Hi all,
I have a really old velux window which needs to be replaced with a modern velux window of the same external dimensions. I’ve contacted velux about which window is the correct replacement but I have no idea who to call to fit it. A joiner? A roofer? A window fitter? Any advice welcome!

A roofer I think.
(If the old one is wooden, are you replacing with upvc? We did that and are very pleased!)

Yes a roofer. Some of the slates/tiles will need to come off to redo the flashing, there won't be any carpentry involved

Thanks everyone!