How do I remove / delete a pencast from Livescribe Online?
Access your Echo/Pulse Livescribe Online personal profile (90010 - How do I access Livescribe Online and my personal profile?).
Under "My files" on the right side of your profile you can remove a pencast you have uploaded by navigating to the thumbnail you are removing and then clicking the circled "x" in the lower right corner of the thumbnail.
Once clicked the thumbnail will disappear. This confirms that your uploaded file has been removed.