How to Edit the Stock Levels of a Product Option

While editing a product in the Manage > Products section, the "Product Options" panel contains a "Product Option Stock Control" button that allows you to set the stock levels of each product variation.

To track the stock levels of a particular Product Option, tick the "Track Stock Levels" box and a list will be generated showing all of the possible variations. You can then set the stock level for each variation. The total stock for the product will be set automatically based on the sum of all variations.
Product Options: Stock Level Button
Product Options: Stock Level Info