Oracle Data Guard 11g - Reinstate primary database after failover

Most time my friends asked me, how to reinstate primary database after failover?
I want answer his question with this video.

My special thanks for my friends from Azerbaijan and India.

YouTube link:   http://www.youtube.com/watch?v=BV-I-J0dqwU
My recomendation is watch video with  720 HD quality.