I'll guess I have to download this into my computer. How do I do that ? Can't find it here.
Follow this link to download Tune ECU:
http://tuneecu.com/TuneECU_En/links.html
You also need to buy the cable. The one you need is the VAG (Volkswagen, Audi Group) group cable. About £7 off Fleabay. http://www.ebay.co.uk/itm/KKL-VAG-409-1-USB-Cable-ECU-Scan-Diagnostic-Interface-Alfa-Fiat-PC-win-7-/301493079004?hash=item4632634bdc:g:4lAAAOSw1vlUu6DQ
Then be careful when you use Tuneecu as things like the "Download" button is actually the upload. i.e. it'll send the tune to the ECU, NOT download from the ECU to your PC.