Replace radio

I took delivery of my barnd new 06 plate Touran SE 1.9 TDI last Monday and it is a delight to drive and own, except for the radio, which is pretty mediocre. I have my own head unit which plays MP3's and has long wave on the radio, which means that: -
(i) I can listen to the cricket on test match special on radio 4 long wave
(ii) On long journeys, like today, my children can listen to my MP3 discs of Harry Potter, and so don't get bored. So I have a pleasant trip!
I went to my local VW dealership to ask how to replace the head unit as it wasn't obvious, and someone from the service dept said to take off the top storage bin, which reveals 2 screws that will get me access to the 4 hidden lugs on the cd/radio. He was wrong. I took out the storage tray but there were no other screws.
Please help someone, as this is spoiling my enjoyment of what is in every other way a fantastic vehicle. Thank you to anyone who can help.:confused: