Einfach mit dem Exiftool und den entsprechenden Parametern für das Schreiben. Siehe Dokumentation.
Writing Meta Information
To write or delete metadata, tag values are assigned using the
-TAG=[VALUE] syntax, or the -geotag option. To copy or move metadata,
the -tagsFromFile feature is used. By default the original files are
preserved with “_original” appended to their names – be sure to verify
that the new files are OK before erasing the originals. Once in write
mode, exiftool will ignore any read-specific options.
Option Summary
Tag operations
-TAG or --TAG Extract or exclude specified tag
-TAG[+-]=[VALUE] Write new value for tag
-TAG[+-]<=DATFILE Write tag value from contents of file
-TAG[+-]<SRCTAG Copy tag value (see -tagsFromFile)
-tagsFromFile SRCFILE Copy tag values from file
-x TAG (-exclude) Exclude specified tag