To be able to enter arena you first have to make the Barbarian Test missions of Ice Islands Quest. Every difficulty got 10 different bosses you have to kill to complete the difficulty. After you completed Greenhorn Arena (easy arena) you can make Scrapper Arena (medium arena) and after that you can make Warlord Arena (hard arena). There are 10 different pits and in every pit you have to fight with a boss. Every time you kill a boss you can go to next arena but if there's someone in the pit in front of you a red rock will appear after killing the boss and you will have to wait until the player in front of you is done. The bosses don't give any loot. They become ashes and then the ashes dissapear. There's a time limit at every boss, if the time ends you are out. To start the Greenhorn Arena you will need to pay 1000 gp (10 platinum coins). The arena is located in north Svargrond, nearby the weapon/armor shop. Go to the ground floor. You will need to talk with Halvar here. Say Hi, Arena, Greenhorn, Yes. After you payed you can enter the doors and then walk to a teleport.
You will meet the bosses in the 10 pits in the same order as shown at Creatures.
If you manage to kill all bosses go to the last teleport.
Go north and enter the first reward room. Take your Bronze Goblet.