Well you can't unless you replace the back cover.
But you can try the guide on the link below (it's for iPod, but probably work for iPad too) but it will void the warranty.
http://www.ehow.com/how_5514217_remove-ipod-engraving.html
Anyway, why do you want to sell it ?
How to remove engraving from ipad?
Dec 19 2013, 01:22 AM
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