Luckily there is an alternative and more underhanded approach: the note mentions a prospective Champion named Klija Wolf-Claw who wishes to fight for the Stormcloaks. These can be taken from snow bears or purchased from hunters and general goods merchants starting at level 10, although at low levels you may have difficulty with this task. If you instead wish to fight for the Stormcloaks, you must bring five snow bear pelts to Yrsarald Thrice-Pierced in the Palace of the Kings in Windhelm. Once you persuade him, you will be handed the Imperial Armory Key to unlock a chest in the nearby equipment room. If your Speech skill is not particularly high, it would be wise to bring a Fortify Persuasion potion with you. Although the note states that the Legion will accept 'any willing soldier', you will need to pass a Persuasion check to convince him to let you act as the Legion Champion.

If you wish to side with the Legion, you must journey to Castle Dour in Solitude to speak with Legate Adventus Caesennius. Both sides intend to nominate a Champion, but nobody has been chosen as of yet. On the counter inside, you will find a note called Battle of Champions, which describes an upcoming battle between the Legion and the Stormcloaks in the ongoing Civil War. Once you've installed the Civil War Champions Creation, you will receive this quest directing you to The Drunken Huntsman in Whiterun. Note: This stage of the quest is only available if you install the Civil War Champions Creation on a character that has not yet sided with the Imperial Legion or the Stormcloaks.

You may have to take out the competition.

How to deactivate champions legion