To Un-install an application from your Kindle Fire:
You can remove an app from your Kindle Fire device, or you can delete it from your Amazon.com account. Apps removed from your Kindle Fire device are stored in Your Apps and can be downloaded again from your Cloud Library. If you delete an app from your account, you'll have to purchase the app again to re-install it on your Kindle Fire.
To remove an app from your Kindle Fire device:
Tap Apps from the Kindle Fire Home screen and then tap Device.
Press and hold the app you'd like to remove and tap Remove from Device.
To permanently remove an app from your Amazon.com account: