Here is an app, that helps the Kindle Fire HD users to install the third party launchers and the Google Play Store.
Full credits will goes to the XDA Retired Senior Moderator, Elite Recognized developer and Godfather of Android Theming Stericson. He is the one who released this app called KindleFree.
For those who have been waiting to get rid of that Amazon home screen, this is the easiest way.Please make a note that to install this app your Kindle Fire HD must be rooted. Using this app you can disable the Amazon home-screen, install a different launcher of your choice, and install the android market.
Both free and paid versions of this app is available in Google Play Store, so it is really very easy to install and use. Another interesting feature of this app is you can remove the things from the Kindle Fire HD by long pressing them.
Click here for Pro Version
Click here for Free Version