This is the what they didn't teach you at university.
CE is very complicated if you don't know what to do; but it's not that complicated if you do professional designs and keep all your documentation up to date and read the EU documentation very carefully. There are places in Australia that will do a fee for service for you to get CE. If you really want to know PM me and i'll tell you some horror stories.
It is too complicated to post an answer that gives all the detail, suffice to say its like mating elephants, there is a lot of noise and sweat for a while then nothing happens for a couple of years.
If you want a real headache try and get something certified in the US, or if really like pain go to Canada, they are worse really pedantic and petty. Don't get me started, I feel a rant coming on....... I'll go and have a bex and a good liedown.