Here's a step-by-step tutorial on using youtube-dl to download and repack Facebook videos:
Although not exclusively for Facebook, these scripts support Facebook video extraction. script download facebook video repack
Automatically combines high-quality video and audio streams. Here's a step-by-step tutorial on using youtube-dl to
Downloading Facebook videos via script may violate Facebook’s (Section 3.2: “You will not … collect users’ content or information … using automated means”). script download facebook video repack