It was the cog wheel icon in the top right hand corner that I used. It is quite a large pdf. 500 plus pages. Sadly, on pay as you go, you are charged for all the data right at the start of the download. If the download fails, or if you terminate, you are still charged for the whole thing. Vodafone did me out of 7 gig in this way. They only did it once. I'm over it now, honest.