Yes, lots of people have done it themselves. If you have a straightforward case, it is straightforward. There is just a lot of document collecting. Have you taken a points test to see how many points you have and if you are eligible for the 189 skilled visa? You need 60 points.
If you have studied in this country you will not need to take an IELTS test, unless you need to for points. I got 20 points for taking the test and getting above 8.