Freesurfer

I'm working on a freesurfer projet. I need a proficient user of Freesurfer to help solve a problem in how to correctly re-process a small sample of 49 subjects with the new version of freesurfer . Unfortunately, I don't have the DICOM files of those subjects anymore. I only have the .mgz files that resulted from processing the images using an older version of freesurfer (v5.0).