I've received a bunch of emails with large attachments and images. I want to keep the emails (including their headers) for my records, but I don't want the attachments and images using up my allotment of storage on Google's servers. I also want to keep my backups small, and they add unneeded bulk to my backup files.
In Gmail, how can one delete attachments/images from emails without deleting the email itself?
To keep this QA generic enough to help everyone, answers addressing sent and/or received emails are fine.