Changing a temporary url

I hope someone can help please. I was given a staging url by our provider, I have finished the site build and now need to make the site live. I’ve tried changing the url’s by firstly changing the settings in the wp general settings and obviously ran into problems. I followed the codex guides (downloading files and databases, changing config.php, uploading files and database etc). There were 7 file transfer errors ((creating directories)) when I tried to upload the files back via filezilla and the was an issue with uploading the database into the new server.

However everything worked for a minute then logged me out and went back to 404.

So I’ve uploaded the original files back to the site, changed the urls back to the staging url within phpmyadmin and am hopefully back to square one without causing to many problems.

Can someone please walk me through how to do this properly?