Do you want the logins?
No, that’s not needed, thanks. I just wanted to make sure you were self hosted – which it appears that you are. That’s a good thing! You should NEVER give those out to anyone online, by the way -not everyone has good intentions! ??
If you aren’t familiar with using FTP, it’s one of the tools used to move files to and from your web space with very little restriction. Here is some good info on FTP clients, and how to get started using one: FTP Clients
In the meantime, you can use the file manger located in your hosts control panel to upload and download files instead. The file manager should have an interface that will feel familiar, and they are usually pretty intuitive.
Log into your hosting account and find your way to the “file manger” options. Then you can navigate to the location where the old file used to be located and upload the new one to the same spot. Your web host should have some information in their user FAQ or knowledge base that can guide you through the steps to get FTP setup for your website (if you want to) as well as instructions for how to access and use the file manager in your control panel.