How to unpack a chrome theme?

How to unpack a packed chrome theme(*.crx)? Their FAQ states how to pack, but not how to unpack.

I got the solution: apparently, a .crx file is just a renamed .zip file. Additionally, when you install it, the theme is decompressed into the chrome install directory...

On Mac OS X, you can use unzip to decompress the .crx file:

unzip extension.crx

Here's the result:

Actually it's more than a zip. When you unzip -l you'll see a message:

warning [extension.crx]: 306 extra bytes at beginning or within zipfile

So the crx file is 306 bytes of something plus a zip archive.

Chrome extension install directory:

Mac:

/Users/username/Library/Application Support/Google/Chrome/Default/Extensions

Windows 7:

C:\Users\username\AppData\Local\Google\Chrome\User Data\Default\Extensions

Windows XP:

C:\Documents and Settings\YourUserName\Local Settings\Application Data\Google\Chrome\User Data\Default

This video explains everything about what a .crx is. In addition to a .zip holding all the extension's resources, it includes a public key and a signature, to ensure integrity and authenticity of the file: Antony Sargent explains .crx files Hosted by: youtube.com

The details of the .crx package format are published here.