Download from SVN
You must have a Subversion client installed before you can use it. (Although you can theoretically download files without Subversion, this would mean tediously downloading each individual file manually.)
The recommended software is the official Subversion client, available from the Subversion project page.
Note that this client uses a command-line interface, which the instructions below use. Alternatively, you can get subversioning software with a graphical user interface such as
is a portable console tool. Extract the zip to your game folder and run the download.bat.