igor5618 solution is great in detail, but I will post my stats as soon as I got the achievement.
I went for all the expert achievements in the game and started with time attack. I did 22 courses on expert, 2 medium, and the rest on hard for my ghosts.
As you can see for my world tour stars I did not have them all when I got the achievement. Everything on the license page gives you % but it is weighted differently i.e stickers are less than world tour stars etc.
But for this specific achievement you should do the time attack on hard (pretty easy) do what you can in world tour on expert (at least all on hard), same with the grand prix, and then focus on stickers/mods
I focused on a single character until I maxed them out in world tour so this one popped before my world tour stars one did
100% Game Completed
227/232
World Tour Stars24/24 Characters Unlocked
10/10
Grand Prix Wins141/160
Staff Ghosts beaten88/100 Stickers Unlocked
80/144 Mods Earned
The ones bolded are the ones that give you the most % but they all do. If you are going for all the achievements then you will most likely get this one either before or right after you get the other ones.
Let me know why if you vote negative, otherwise Happy Hunting