Move files then continue seeding

From AzureusWiki

If you've finished downloading a file (and it has switched to seeding), but you want to move it (out of your download directory, perhaps), then the correct way to do this is:

• Stop the seed (red square button on the Azureus button bar)
• Move your file to the new destination (please note that if your torrent contains multiple files, then you'll want to move the whole directory that Azureus created for it, since maintaining that structure is pertinent to the torrent's integrity)
• Start the torrent again
• See the Status turn to "Error", which you'd expect since the data isn't there any more
• Right click on the torrent
• Pick the Change Data Directory option at the top of the popup menu
• Pick the new directory in the dialog, and press Ok
• Stand (or sit) and be amazed, as the torrent goes to its expected state, with stats intact

Note though, that the Change Data Directory option doesn't show up until Azureus notices that the file is missing. It expects you to move the file first, then update the path to it.