Get a bow or some decent spells. Make sure you have at least 30 in Acrobatics. As soon as the gate drops, run to your right, to where the right gate meets the fence. Jump onto the stone piece that juts out. Then, jump again to get on top of the little piece sticking out above it. Once on top, turn and fire on your helpless victims. When you have to fight mages or archers, stay on the ground and strafe behind the four central pillars for easy kills.
Make sure you are already a Champion in the Arena. Talk to the Grand Champion about his nobility and how he needs proof of his nobility. He will send you on a quest to Crowhaven and give you a key. Use the fast travel system to get to Anvil. You will then need to travel northwest to get to the Crowhaven ruin. Beware of the skeleton archer and skeleton guardian. The archer is easy, but the guardian is not. Just block and strike. You will eventually kill the guardian. Once you get inside the ruin, watch out for wolves. There will be one to the right as you enter. Just follow the path through the ruin, killing the wolves and skeleton archers. There will be a gate that needs a key, but the Grand Champ already gave it to you. Unlock the gate and walk through. The only "monster" will be a half naked man with an Elven dagger. Take your time and block and strike twice. Do not underestimate the little dagger. Once he is dead, find the journal. Your quest will be updated. Once you go out of the gate that you unlocked with the key, there is a door down to your left. Beware, as there are three vampires and one wolf. The vampires will give you a disease. There is not anything special down here, and is an optional area . Exit the ruin and fast travel back to the Arena. Talk to the Grand Championand he will become extremely depressed and not want to live. Challenge him in the arena. Talk to Ysabela about the challenge. Go up to the Arena. Once the gates drop he will charge at you. However, he will not attack you. He will tell you to kill him to put him out of his misery. Hack away at him. Once he dies you will get got an Elven longsword and Dwarven shield (heavy). Bring back his Raiment Of Valor to get your own.
Go to the Imperial Arena and place a bet with the gatekeeper. The best amount to place is 100, as you are guaranteed to win. Then, go through the door up to the balcony where you watch the fights. While the announcer is giving the intro speech, Quick Save the game. Let the fight go through. If your fighter did not win, select Quick Load. The fight will be different each time. Repeat this until you win the fight. This will always allow you to walk away with your pockets full.