Here are a couple of options of how to get to the venue from the airport (Arlanda), based on price, availabilty and comfort:
1. TAXI - May sound like a pricey alternative, but if you choose the cab company 020 (yellow cabs with blue letters) they hav e a special deal with the hotel and the fare is only 260 SEK (approx 30 EUR). If you split that cost in 4 you can get to the hotel for not even 9 EUR/person.
2. This section is divived into 2 parts:
Option A - Take local bus 583 towards Märsta station and then change to any commuter train headed to Stockholms Central. Jump off at Upplands Väsby and then take bus 530 to Kallhäll, 536 to Bollstanäs or 566 to Infra City. If you are uncertain. Ask the bus driver. This option, although cheaper than the cab, especially if you are traveling alone, can be kind of complicated though. Not only because of all the switches, but also due to ticket regulations in Sweden not allowing you to pay for the bus unless you have a prepaid card. You have to purchase one at the store Pressbyrån before you get on board or buy a single ticket there. The benefit though, aside from the price (approx 50-60 SEK for a single ride) is that if you are sightseeing before or after the event you can use the same card and recharge it.
Option B - Similar to above, but you take the commuter train straight from Arlanda. Departs from the area called Sky City. You get off at Upplands Väsby and from there repeat the same procedure as option A. The benefit is that you shave of one bus ride which depending on the amount of luggage can be useful. The downside is that without a valid monthly commuter card, the train ride alone is 125 SEK and then you still have to get a prepaid card to get on the bus. NOTE! This is the least recommendable option and should only be used during special circumstances. Although we can't think what those would be...