1. First you need to login heroku:
heroku login
2. Then you need to download the code:
heroku git:clone -a <project_name>
3. After you done your changes, cd to project root folder:
cd <project_name>
4. State the changes:
git add --all
5. Commit the changes:
git commit -am "make it better"
6. Pust the changes:
git push heroku master
[Heroku] How to pull, push changes
原文：http://www.cnblogs.com/Answer1215/p/4212379.html