Winter is coming, and Parse is shutting down on January 17th.
If you still need to migrate your files out of Parse and into your own S3 bucket, check out my solution:
https://github.com/slidebean/parse-s3-migration
Parse provided their own utility app to perform this migration. However, at the time of this writing, it hadn’t worked for me at all. I based my solution off theirs.
Good luck!