Format: xdelta3 -d -s "base" xdelta file source "location".
You may need to download Xcode for Homebrew to work, which is on the Mac OS install disc.Open Terminal and type “ brew install xdelta”.To patch xdelta files, you’ll have to download the xdelta program, which can be used through the Mac’s Terminal program (the equivalent of Window’s Command Prompt). (The GUI might be unresponsive when you select the ISO file and when you patch the file).
Windows (GUI Patcher, Courtesy of cixota)
Special Thanks: arisu, Rivalee Download Full Patch (349 MB)