If you want to mark a product as inactive in Newegg, complete the following steps.

1. Go to the Feeds tab from the top left navigation bar
2. Select the NewEgg feed template
3. Select Rules in the setup section of the sidebar menu within the feed page
4. Set up a rule to set "ActivationMark" to "FALSE" for the desired products 
5. Set up another rule to set "UpdateType" to "Update/Append Image"