How can we move mountains by faith?

What does Jesus mean when he says to have faith as a mustard seed? 

These questions have always came to my mind the first time I read Matthew 17:20:

"So Jesus said to them,

“Because of your unbelief; for assuredly, I say to you, if you have faith as a mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move; and nothing will be impossible for you."

Today I would like to answer both questions from my experience and my faith. 

(1) How can we move mountains by faith? 

(2) What does Jesus mean when he says to have faith of a mustard seed?