Alfresco is not very good at uploading of files larger than 2 GB in size via the frontend or via the API. The best option for uploading larger files is via FTP.
Instructions
Add the below lines to alfresco-global.properties file and restart Alfresco
ftp.port=2121
ftp.enabled=true
Then you can login via an FTP client like WinSCP of FileZilla, using standard username and password of Alfresco user accounts.
Only use FTP protocol to connect. SFTP or SCP won’t work.
Ensure that port 2121 is open in server and cloud provider’s firewalls, and also outgoing connections to 2121 are allowed from client network.