Easily split large Apple ProRes 422 HQ files
I had old 8mm film-based movies of historical significance to us digitized by a company and they provided me with Apple ProRes 422 HQ files...VERY LARGE files. Some are 50-60 GB or more in size. I think they may have joined a number of 50 foot reels to one file. This causes me problems when I wish to upload them to a cloud for backup/archiving off-site. A file that large can take a long time and has to be restarted if there is a problem during upload. Or the cloud service may simply not allow files of that size.
What is the best way to break these into smaller clips without losing ANY quality in case they are needed in the future for new productions or editing? I'm a video editing novice. I bought Final Cut, but it's overwhelming to learn to do this.
Is there
(A) a program that would simplify this job, or
(B) is there a simple step-by-step workflow in FC that you could point me to?
I'm using an iMac and/or a Mac Pro running 10.11.6 El Capitan right now for this project.
iMac, OS X El Capitan (10.11.6), MacPro, MacBook Pro