You can do this using bulk edit in Seller hub.
You don't have to be a business seller to use seller hub.
From your Ebay page, choose 'selling' then find and select 'switch to all new selling view'.
Choose 'selling' then active listings.
Then 'bulk edit' and 'delivery'
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)