Go to the Central Station of Stockholm, grab snacks for the trip, and check into the night train bound for Kiruna and the Arctic Pole.
Suggestion: first class cabin ticket with bathroom & shower
We decided to take a First Class cabin on the night train as we wanted to enjoy the journey by our selves. It’s not the cheapest, and we had friends sharing their cabins and loving the idea. It’s a choice, no right or wrong but we can say the first class cabins are really worth the price in terms of comfort and experience.