Open the function menu of the product you want to delete and click the corresponding item.

Important! Deleting a product will delete all associated licenses and activation codes. Users will no longer be able to activate the software. Note that even if you recreate this product from scratch, this will not allow your old users to activate it, because the RSA key pair will be different, effectively rendering old keys invalid.
If you want to temporarily stop all activations for a specific product, deactivate it instead.