After turning in Welcome to Cyrodiil to Zan at the Siege Range, he will give you the quest Siege Warfare. He will tell you to try out all the siege weapons. Simply hit the target dummies using the catapult, ballista and trebuchet.
It is optional to speak to Firamo and Miniel. They will just give you more information about the siege weapons.
After using all the siege weapons, talk to Zan again. This time he will hand you a Practice Repair Kit to use on the siege weapons. To do this...
- Press I to go to your inventory
- Click on the Quickslot tab on the top right hand corner of the inventory window
- Place the Practice Repair Kit into one of your quickslots
- Get close to a siege weapon and press Q to repair
Rewards: Limited Dominion Forward Camp, 200 Alliance Points, 160 gold