Activate Krark-Clan Ironworks by sacrificing Sword of the Meek, adding ({C} magic symbol) ({C} magic symbol) .
Skittering Precursor triggers, creating a 0/1 Eldrazi Spawn creature token.
When the Eldrazi Spawn enters the battlefield as a 1/1 due to Street Riot, Sword of the Meek triggers, returning Sword of the Meek from your graveyard to the battlefield attached to the Eldrazi Spawn.