RE: Building Instructions for Extra 500 ?
What you got are the only instructions available from the factory.
See: [link=http://www.fly-model.com/cp_detail.php?id=21269&nowmenuid=1243&cpath=0262:&catid=0]Click me![/link]
I've built a bunch of Fly model planes, and most are very straight forward, assuming you have prior ARF construction experience.
I would suggest getting help from a club member who has put together many ARF's.