In reply to Chris Aston:
Route finding isn't generally too difficult.
Don't confuse the little tower with the great tower.
The main points of interest on the route are:
Initial chimney
Small buttress further than chimney
Little tower
Great tower (including the eastern traverse)
Tower gap
There's usually a sling(s) around the block before the gap and you can clip into that as you climb down.
We did it without pitching anything in around 2hrs (I don't know whether that's fast or slow).
Check the conditions before you go to make sure there's not too much snow left over from winter (if you're going in summer you should be fine).
Follow the crampon scratches like someone said before!
Have fun, it's a great day.
Post edited at 19:55