Assessment test is english and stats test. If your english is bad, please read some english books or practice some writing. For the stats test, speed and fast-thinking comes in handy. Don't worry about finishing the stats test, it's impossible to finish.

For the interview, the most important is to bring your passion and show your eagerness. I've heard of people who were not interested in the jobs they're applying, but they went for the interview regardless. And their lack of enthusiasm for the job shows. Sometimes, the interviewers will ask "What do you think is your weakness?" Don't say you have no weakness cause that's not believable. Admit you have one, and explain it in a positive way. For instance, I said that I'm bossy, but that's only when I deal with people who miss deadlines and because I like things to be perfect haha.

Actually, I don't have much experience myself, this is all based on my observations. Keep in mind the people who will interview you are people who have been working at the company for 8-10 years at least. In a place like the big 4, to survive that long means they enjoy their job even though it's tough. So when they interview people, they want to look for people who will enjoy their job as well. I don't know how relevant this is to an audit interview, since I'm not in audit. But I've had friends who interviewed at other places, for other job descriptions. One told me that the director who interviewed her could sense right off that she wasn't interested in the job. Of course if you're just interested in this job just for the benefits temporarily, just fake the passion la haha.

Also, they won't ask technical questions. When you come in for your assessment next week, they'll start off with a talk about PwC. In it they will say that what you learn in uni is not really applicable to work. So they won't expect you to know such technical stuff such as audit methodologies. Although if you can chat with your interviewer about it, they might be impressed. Keep in mind every interviewer is different and will ask different things.
xxDingxx, I think that this advice is applicable to most companies.. Just don't be so nervous at the interview and smile. Deloitte is understaffed at the moment, so unless you wear jeans to the interview, never take a bath for a week and frown, the chances of you getting in is high.

no tips. just be yourself. that's all i can say. that's because u cannot predict what questions will be thrown at u. some people say 'oh u need to know all the FRSs, guaranteed to be asked'. well i can prove u wrong cause all my interviewer asked was about my life in UK.

but yeah like morgana said, just be confident and one important tip for ya. Get to know who is your interviewer and great him/her by her name and followed by a firm handshake. After you're done, thank them again for their time makes a good impression that u've went all the way out to find out who is your interviewer