This is how superglue corporation answers the question, try this link-
http://www.supergluecorp.com/removingsupā¦And many people says an acetone-based nail polish remover or professional grade acetone or even a thinner, that is available in paint shops, can do the job well. Apply some to the glued area with a cotton swab or cotton ball. Use a fine needle and scrap at the joint to remove the excess Feviquik, until the cover comes off.
Or i think this website gives some more ways to remove 'crazy glue.'
http://www.ehow.com/remove-krazy-glue/ Don't worry. All the popular industrial glues like super glue, feviquick, crazy glue belongs to the same family. Because they all're CA glues. So try it.
Even after posting all these help links, i'll say, you better change the n8 cover. ;)