On Wed, 13 Apr 2011, Thomas Schmitt wrote: [..]
A simple solution might be little de-MBR programs in some widely available interpreter languages, which get offered for download together with the images: Seek byte 0, write 32 kB of zeros, keep all other bytes unaltered. In any language this would run much faster than the dd copy method.
dd with conv=notrunc should do the trick. Of course, that way you change the file in-place ("make a backup first, if you want to keep the original").
Also, publishing an official md5sum of the patched file would be a good idea.
Best regards, Anne Bezemer