From what I know, it is as follows :
1. Day 1 - Interview in the morning ( pretty straightforward stuff asked). If successful in that, you do a Sim assessment in the afternoon. Again, fairly straightforward. It'll be on the A320 I've heard.
2. Day 2 - Is successful in both interview & sim on day 1, you are required to undergo a CAAC Singapore medical Exam. If successful in that, apparently, thats when they offer you the position.
Good Luck