If you have more than one hosting account, you can move files from one account to another using FTP and your own computer.
To get started, you'll need to transfer the files from the first hosting account to your computer (download). You can save each file one by one using your browser, but we recommend using FTP to connect to your account and download all of the files to your computer at once. FTP prevents you from accidentally downloading any code that doesn't belong to your pages and allows you to easily copy not only your web pages but also your images, audio clips, and other files.
Once you have saved the downloaded files on you computer, you can transfer them to your second hosting account (upload). Use your FTP tool to connect to the second account (be sure to use the unique settings for that account — the settings you used to connect to your first account will not work), then use your tool to transfer your saved files to that account.
Tip: If your Web Hosting accounts are associated with the same Yahoo! ID, you can manage them all from the Web Hosting Control Panel using the "Select a Site" menu near the top of your Home tab. Just select the domain associated with your other site and click "Go."
If you signed up for a Yahoo! Web Hosting Basic plan, you do not have the option of using an FTP client. In order to use an FTP client, you need to be signed up for either Yahoo! Web Hosting Advanced or Premier.
NOTE: As of February 19, 2013, Yahoo! Small Business has completed the transition from supporting FTP to FTPS. To avoid any connection issues, please make sure you have updated your FTP client to use your FTPS settings.