Hi On the brakes,
if you haven't attended the assessment yet, the only thing I feel worth to tell you is ... have a thorough look on the thread "
Ryanair Interview and Sim Assessment (merged)" and indeed do your best to prepare. Once you get there, I can bet you anything that You will be more than surprised on how good, kind and cheerful the whole Ryanair' staff is. So no reason to panic !
Best of luck,
fredgrav