Frogga, don't worry too much about the second stage.
Learn the motivation paper back to front, prepare for some standard interview questions and you'll be fine.
With regards to the computer tests, don't worry about them. The aim of the game is to keep plugging away even if you think you are doing terribly. They, in my opinion, are designed to put as much pressure on you as possible. You will feel as though you have made a complete arse of it, but rest assured, you will not be alone in feeling like this!!!!
So, to summarise, ace the motivational paper, give good answers for your interview (which only lasts about 20 minutes) and keep going with the computer tests.
Then stage 3 comes.....hehehehe!!!!
Any questions just give me a shout buddy
Kev