You have been asked to prepare the Jangovars' weapons for a dwarf attack.
'I have another task for you, Chayasír. Unsurprisingly, the dwarf weapons are in excellent condition, but our own weapons are in need of repair after the battle at the Lonely Mountain. Spears need to be sharpened and polished, and bows strung tight. I leave this to you, but do not tarry. We need to be prepared for a dwarf attack.'
Jangovar spears and bows can be found around Utterby.
You should sabotage Jangovar spears and bows.