I thought the whole idea of burning a book was to offend someone who holds that book dear. Why would we need to destroy our own stuff just to piss someone off?
The only reason I would delete the Koran would be the same as any other book, if it was taking up space I needed or was a poor copy.
So if you feel the need to offend someone you will have to do the deleting in a public place, preferably with TV cameras watching so you know you can piss off as many people as possible.
More better you get yourself a paper copy and burn it properly. Just make sure there are lots of people watching, and you give the event plenty of notice and publicity. You don't want to miss out on a potential offendee not seeing it!
Seriously! Some people are extreme dickheads!