oh ok. (darn, thought it was possible for me. oh well)
It's quite possible.
Simply figure out how the game draws the title. The title is made out of 8x8 blocks just like fonts, it's just a matter of finding out their hexadecimal values and see if it's possible to rearrange them. And if you can do so, then you can copy your new title screen onto the space used by the tiles on the ROM, and rearrange them one by one.
It's a lot of hard work, but it IS possible. I've done several title screens that way, and I'm not programming expert.