It's pretty easy. Just buy the ticket on mu-mo Live with a card and you are set! Making the + account is easy as well.
https://live-on.mu-mo.net/oauth2/authorization/mumo_id
This page should lead to some account creation things on the left side, better to view with Chrome and from there you can make an account with various social media or email and then after that you just log in -> buy ticket and wait till 10/2!