Extensions can be loaded in unpacked mode by following these steps:
Visit chrome://extensions (via omnibox or menu -> Tools -> Extensions).
Enable Developer mode by ticking the checkbox in the upper-right corner.
Click on the "Load unpacked extension..." button.
Select the directory containing your unpacked extension.
The crx file needs to be extracted first. CRX files are zip files with a different header. Any capable zip program should be able to open it. If you don't have such a program, I recommend 7-zip.
