Recoding the video itself is fairly complicated. If you just need it transfered, two options. One, reformat your external drive as NTFS (assuming you're using windows) because it can support single files larger than 4GB, whereas FAT32 (what most drives use by default) can't. Other option is using winzip or winrar, and make a multi-part archive. This basically splits the file into pieces, and at the other end, you can use it again to extract the original file from the parts.