Elleen A. relates,
I have 2 male fully flighted cockatiels that will not let us handle them. They are bonded. How can I get them to let us handle them again?
Short answer. You can’t. Birds of a feather stick together and you have no feathers.
You can clip their wings, separate them into different cages, and plan to spend several hours with each of them individually in daily sessions in hopes to earn their trust and want to be with you.