Change Boot Screen on Win x64

Like the title says, does anyone know how to change the booting screen for Win XP x64? There are a bunch of programs out there that do this kind of thing, but they're all 32-bit only. I found a neat program called Bootskin but sadly it's also 32-bit only.

I also know that it's possible to do this manually, but they involve messing around with system files (kernel). Any help on this is greatly appreciated.

I think there was a guide on G4 tech tv or something I saw recently. If I find it, I'll post it. They did it the manual way though. The main thing they said was to keep a backup copy of the boot screen file incase the other one messed up.