I am wondering if anyone has run into this problem before, and has a solution.

We are trying to post-hoc anonymize FreeSurfer reconstructions. It's a simple matter to move the reconstruction directory, as well as to replace any instances of the old subject ID in text files (e.g. stats or log files). However, when I open any of the binary files (e.g. lh.pial) in a text editor, the last line includes the mris_make_surfaces command called to make the surface. This includes the old, pre-anonymized subject ID. I am worried about reading & writing these files using an ASCII editor, because I don't want to corrupt the binary encoding. Additionally, because the binary format is not public, there appear to be no tools to read & write to these ASCII tails in the binary data. Is there a way to either strip these lines, or to replace the reference to the old subject ID with the anonymized ID (this option is preferable)? Ideally, we don't want to have to reconstruct every binary file using the updated subject ID.

Thanks for the help!