How to create a patch and apply to your module (Drupal 7)
I found two links that help me a lot.
1. Create a patch: https://events.drupal.org/losangeles2015/sessions/how-when-and-why-patch...
The file included in that website: How When Why Patch Module.pdf
2. Apply a patch/ Revert a patch : https://www.drupal.org/node/620014
Hope I can have time to write a blog for this.