How to update Product Attributes

Select Catalog -> Manage Products from the main admin menu.

Select the Model from the Product list that you want to make changes to by selecting any line that product is on in the table.

From the product menu on the left select the Custom Options tab. This screen may take a second to load all of the available attribute options. It will then show all of the custom options available currently for that model.

You can then scroll to the custom option you wish to add or remove attributes from.

From the list on the bottom left of the custom option you want to update, select the options you wish to add.

Then click the +Add New Rows green button.

If you want to remove an option, select the DELETE ROW blue button on the line that relates to the option you want to remove.

With the new custom options that have been added you have the option to add custom pricing, custom group pricing and customer group excludes.

Repeat the process for all options you want to add attributes to/remove from.

Once you are happy with the updates, click either SAVE or SAVE AND CONTINUE EDIT green button at the top right to save your progress.