You must go back to the quest giver and accept the quest again. Or if possible, have a friend in your group share the quest with you.
you cant
If you mean that you have destroyed the cask but kept the quest, the only way to get it back is to return to the questgiver in Westfall, abandon the quest and retake it from the Dwarf. I do not think the quest itself is repeatable, so if the quest is completed, you cannot do it again.
no
you have to go to a website and download quest helper. i recommend you google "WoW quest helper download"
Impossible
You will get the quest once you have done all of the quest line in Dragons Blight. At the end of the cut scene the dragon queen will send you back to Borean Tundra which will then send you to Thrall in Org to pick up the quest Battle for under city.
Quest and do your lvl instances
Look around the area for a weapon rack that has "sparklies" on it, denoting that that rack has a weapon on it. These will be the quest item you are looking for. Grab one of them and take it to a Runeforge. There are several around there. Open your bags and right click the weapon that you took from the rack. This will runeforge it and complete the quest. Turn the quest in back at the quest giver.
Hss bow wow does want ciara back
As a part of the transition from Mists of Pandaria to Warlords of Draenor, we'll be making some changes to the Legendary Cloak quest line.
WoW, Ragnarok Online, etc.
He used to be part of a level 10 warrior quest. This was back way before WoW 2.0 came out. As of now, he does not do anything. More info in the related links.