1. Go to Products.
2. Click on Stock.
3. Find the product you need to change the stock level for.
4. Make your changes.
To increase the amount of stock, select Add enter a positive number.
To decrease the amount of stock, select Add and enter a negative number.
If you don’t want to add or subtract an amount but instead want to just set how much stock you have for that item, enter an amount and click Set. You can enter a negative amount here, this is useful if you are allowing pre-orders on out-of-stock products.
5. Click that product’s Save button.