1. Unzip DeliveryDateMap-Chrome-Extension.zip (you get a folder called DeliveryDateMap-Extension).
2. In Chrome open chrome://extensions and turn on "Developer mode" (top right).
3. Click "Load unpacked" and pick the unzipped DeliveryDateMap-Extension folder.
4. Pin it: click the puzzle icon in Chrome's toolbar, then the pin next to Delivery Date Map.
5. Open any Amazon product page, click the icon, and sign in once with your Delivery Date Map account (email + password, or your team code).
6. Updating from the old Buy Box Map extension: remove Buy Box Map in chrome://extensions, then load this folder. Updating Delivery Date Map later: unzip the new file over the old folder and click the reload arrow on Delivery Date Map in chrome://extensions.
