Most Helpful Guy
Options 2 or 3 probably best. Be yourself and be open with him. Option 1 means you have lost the chance already, but with 2 or 3 ( or maybe 4 as well ) you have lost nothing if he's not interested. In which case you can move on and find another guy.
Most Helpful Girl
Just go up to him and ask him a random question so you can talk to him. It is best to do things personally because he might think your friend likes him. And trust me it hurts if he falls for her.
You do not want to wonder what could have happened.