This guide assumes that you have a basic understanding of how a file manager and FTP works, otherwise we strongly suggest you use the web interface located at

Image files can be accessed via FTP (File Transfer Protocol)

Port: 21
Transfer Mode: Passive
Username: your username
Password: your password (if it errors try your password in lowercase)
We recommend FileZilla FTP client it's free and support Windows, Linux and MacOSX.
You can download it here:
Filezilla also support multi download and on the fly compression MODE-Z.

To turn on multi download transfers in FileZilla:

1) Click on 'Edit', then 'Settings'
2)  'Transfers'
3) Under Concurrent transfers - Maximum simultaneous transfers
4) Set the value between 2 and 10. This is how many files it will download at once.