Altering Outdated Chrome Extension Source Code

Today I tried to install/load into chrome an old extension that was not on the offical chrome market. Chrome will now only allow apps on their market to be installed. So I downloaded the .crx extension package, unpacked it into a directory with winrar and then went to settings -> extensions -> load unpacked extension from chrome. When i  did this i got an error about a manifest 1 not being supported. It was a simple fix, just add a line of code in the manifest.json that is in the unpacked directory.

Now i can play my apple IIe emulator in chrome.
http://www.virtualapple.org/rockysboots.html

Manifest Version

Extensions, themes, and applications are simply bundles of resources, wrapped up with a manifest.json file that describes the package's contents. The format of this file is generally stable, but occasionally breaking changes must be made to address important issues. Developers should specify which version of the manifest specification their package targets by setting a manifest_version key in their manifests.

Current Version

Developers should currently specify 'manifest_version': 2:

{
  ...,
  "manifest_version": 2,
  ...
}

Manifest version 1 was deprecated in Chrome 18, and support will be phased out