Freesat on Panasonic G10

Ok, I bet this has been asked before, but I need to be told in simple terms how I can use the built in Freesat on my G10? I already have a Sky HD box, which is perfect, but am keen on seeing some ITV in HD especially the football. So can this be set up without disturbing my Sky HD, or have I got to swap cables around etc?

It's also got built in Freeview, is it worth it? can I use this as well? or am I getting carried away?

Thanks,

Dr.