You have to do it on a computer. I don't think you can delete it directly from the Nook.
To delete trash messages on a Nook device, navigate to the "Library" or "Home" screen and locate the "My Files" or "Messages" section. Select the trash or unwanted messages you wish to delete, then look for the delete option, usually represented by a trash can icon or a "Delete" button. Confirm the deletion, and the messages should be removed from your device. If you're using a Nook app, the steps may vary slightly, but generally, you'll find similar options in the app's settings or message section.
take out the battery or turn it off and reset it
you go to the barnes and noble website and sign in to your account (the same one that is registered onto your nook), and then you go to my account, then my NOOK library. that will bring you to a page where you can delete any of the books off of your nook.
Not every app, but you can still get a lot of apps on the Nook.
You can find free Nook apps on the Barnes & Noble website or in the Nook app store on your Nook device. Simply search for "free apps" in the app store to browse and download a variety of free apps available for your Nook.
To delete pictures on a Nook Tablet, open the Gallery app and navigate to the album containing the photos you want to remove. Tap on the photo to select it, then look for a trash can icon or a delete option, usually found in the menu or at the bottom of the screen. Confirm the deletion when prompted, and the selected photo will be removed. You can also delete multiple photos by selecting them first before tapping the delete option.
you cant it never comes off
Delete history on nook hd
Not at this time.
1. Put finger on the app you want to delete 2. Hold finger there until the app starts vibrating 3. Press the "x" that appears on the top left side of the app 
well mabey if take a shower for once I'll tell you
To delete a mixtape from the My Mixtapez app, open the app and navigate to your profile or mixtape library. Find the mixtape you want to delete, tap on it to access the details, and look for an option to delete or remove it. Confirm the deletion when prompted. If you encounter any difficulties, consult the app's help section for specific guidance.