This cheat requires the Fighters Stronghold expansion from the Xbox Live Marketplace.
First Kill the Marauders that are attacking the stronghold. Once done with that, talk to one of the Battlehorn Man-At-Arms, and they will give you the deed to Battlehorn Castle.

Next, go and buy the castle upgrades at the Merchants Inn in the Imperial City Market District. Be sure to buy the training room upgrade with it will come an Orc fighter and a bunch of assorted weapons, like swords and maces.

Once you do this go to the basement and look for the training room, set the difficulty setting to its highest and pick a weapon to fight with.

Talk to the orc and choose to spar with him, he'll ask you to pick a weapon, choose either of them. Now you'll start fighting him.

Don't worry about your health, you won't get injured by the orc's attacks only he will, and don't worry about killing him because he only be knocked unconscious.

And if you break your weapons either repair them or get one of the weapons lying around the training room. That's all there is to it.