Some Shipping Methods found All Orders are currently found grayed out not allowing you to edit/modify, inactive, nor delete them.
This is because Quickbooks does not allow this is happen. You need to make the necessary changes in Quickbooks.
In QUICKBOOKS, you can modify or make the Shipping Method inactive but it does NOT allow you to delete it. Once you have made the changes to Quickbooks, the changes will then reflect in All Order after you synchronize.