You're talking about the black box at the top of the spine, right? Depends entirely on the complexity of the actual source material. Stuff like the Zelda boxes would be easier, since it's just a gold-ish color that would need to be pasted over it, while others would need to be rebuilt or re-scanned.
I think most people prefer the TCP box at the top of the spine (myself included), since it lends a feeling of uniformity to an otherwise ass-random kaleidoscope of whatever the publishers originally felt like.
