Files that big (normally) shouldn’t be uploaded using standard file fields like standard sized files. The vast majority of servers won’t handle anything that big and will choke on the data before the file is even finished.
The best way to have it work is to use FTP to upload the files to your server. That will work on any sized file, and as long as you have the storage space on your server, you’ll be fine. As long as you know the folder that you upload them to you’ll be able to get the URL sorted out.
If you really need to upload files that big, there’s a range of scripts for uploading large files. A quick search finds a lot of results –
https://www.google.com/search?q=large+file+uploader+script