How to view or edit localStorage
It's simple. Just go to the developer tools by pressing F12, then go to the Application tab. In the Storage section expand Local Storage. After that, you'll see all your browser's local storage there.
Open the Developer Tools by pressing F12.
Click on the Application tab and you will see localStorage's content. From there you can add/edit/delete the entries manually.
On OS X the keys are: ⌥ + ⌘ + i
Another combination: Ctrl + Shift + i
In Chrome it looks like this:
You can go to chrome://chrome/extensions and there will be a link to your background page that once you launch you can use the Dev Tools to see the localStorage stuff.