If you have trouble downloading from Mega (due to file size limits) go to Go File and choose "Open" rather than "download". You will then be able to download the 4K version and/or the 1080 version individually.
(If you try to download the whole thing at once via Go File you will run into a paywall but if you download the 4K and 1080 versions individually by opening the folder first, you won't have that issue.)