I initially applied for the position online. Make sure you have your transcript handy when filling out the application as there is a section to attach at the end. A cover letter wasn't required, but there is a space to attach one (obviously recommended).
Once I applied online, I heard back within a few days requesting I complete both a numeracy test (math) and logical reasoning test (though I think now they might just require the math test). The math test isn't technically difficult, but you need to be very quick with your calculator (no fat-finger mistakes!!) as the rest is timed and is designed so that you can't spend more than 30-45 seconds per problem. There are websites out there that allow you to do practice tests, and I highly recommend you start practicing before you even submit your application. Once they send you the link to the test you only have about 5 business days to complete it, so if you wait to start practicing until you get the link you won't have much time to spend practicing.
If you pass the online test you will be invited for a video interview. This interview was pretty difficult in terms of the questions they asked (Explain your favorite recreational activity in fewer than 10 sentences, describe a goal you set for yourself that you didn't achieve, name 3 words that describe you, etc...the list goes on).
If you pass this stage you are invited to a half-day interview with 10-15 other candidates. They do several of these day-long interviews, so your day won't be the only day of interviews. You'll notice many students from certain Universities they recruit heavily from, but everyone was super nice when I interviewed. You'll probably have 2-3 one-on-one interviews with people from across the business. They are friendly and the questions weren't too difficult (though be ready for the guesstimate a # curve ball). You will also have a case study where they give you the details of a business question and you have 45 minutes to compile answers to a list of set questions and then a half hour to present your findings. Don't just stick to the questions though when you're preparing, as they will deviate from the list to keep you on your toes and make sure you've thought through multiple scenarios.
Depending on when your group is scheduled it may take a while to hear back. I didn't receive an offer and got a form email saying I wasn't chosen.