How does change happen?

When each of these 3 things are present, you cannot not change...

1.NEW AWARENESS. 

If you can't see it, how can you possibly change it? All change begins with seeing things with new eyes.- A light bulb moment,- A new perspective- A great question that unlocks a whole new level of learning- An understanding of WHY you are doing what you are doing. 
The proverb says "Seek understanding like silver and search for it like precious jewels..."Be prepared to ask, seek, doubt, let go of being attached to a certain way of thinking and living.

2. MORE CHOICE. 

We are all trying to bring peace and comfort to ourselves the best way we know how. If we had a better way, of course we would use it. More choice comes every time we listen to wisdom and learn a better way. It flows out of the experience of gaining new and deeper awareness. It comes from realising that being stuck with limited choice is simply an illusion, and that we each have 100% choice about the things that matter most in our lives. 
Never stop learning. Embrace 100% choice. Be willing to let go of the old way every time you find a better way.

3. ALTERED BELIEFS. 

Behaviour comes out of belief. It never lies. It proves what you really believe to be true, or important. Therefore if you're new awareness leading to increased choice, alters what you believe is true, what is right or what is best, then your behaviour is automatically changed as well. 
Dr Ian Snape taught me that all beliefs exist on a probability scale from 0 - 1. 0 is 100% not true and 1 is 100% absolutely true. Now seeing that we never have access to that level of certainty, we are left to live in the grey in-between. Based on our understanding, learning and experiences, things are either highly likely to be true, highly unlikely, or somewhere in the middle. 
Every time we have experiences of increased awareness and more choice, our beliefs slide up and down the scale. They are highly mobile - Not immovable forces. I'm sure at one time in your life you believed that the existence of Santa was highly likely, but that belief has probably slid down the scale to now be highly unlikely. As a result of this, your thoughts feeling and behaviour around christmas time automatically change too. 
So embracing new awareness and more choice, leads to altered beliefs. 
Changed beliefs = changed behaviour. 

If you are trying to cause change to happen in your life and your awareness hasn't increased, you don't have more choice and your beliefs haven't altered - then that is the very definition of pushing shit uphill. 
Good luck with that...