Shortest method to upload database to server
Personally, I'd do it using a compressed backup file.

Install an (Express will do) instance of SQL Server locally and run the script. Then, back it up and compress the backup file with a good utility (7-Zip/WinRAR compress very well and can create self-extracting archives). Transfer the compressed backup file (e.g. FTP), uncompress and restore the backup.

You can also compress just the 3GB textual script file and compare to see which is smaller to transfer.