strip jpg-preview subfile from raw

[freakout]

these new 24/36-megapixel monsters produce very large raw files.
even the embedded jpg-preview files are considerably large ~3mb!
it would be very nice to strip these large jpg-previews from the raw,
expecially for all lightroom users where the previews are cached by
lightroom and all these embedded preview jpg waste disk space.
is there a way to extract the preview subfile and write the raw with
all other exif lossless conserved?

[Phil Harvey]

Yes.

Sorry, I can't be more specific until you tell me what type of raw file we're dealing with.

- Phil