This Python script will take work items from your CodePlex project and import them into your GitHub project. It also includes comments.
In order to run this script, you will need to
download the github2 library and
install it.
You will also need a GitHub API Token - you can get find yours
on your account admin page
Finally, edit the script file and modify the values at the top to include the details of your projects.
I suggest creating a test repository in your github dashboard to test the import against.