In order to change the owner of a function, click on the checkbox to left of the function name and click Change Owner. Upon clicking Change Owner link a popup will appear that shows all of the users to whom you can assign the selected function to. Once you select a user from the drop-down presented and confirm, that user will become the new owner of the function. Only owner of the function and a user with admin role can perform this operation. In case you are changing the owner of an entire folder, you will be prompted to change the owner for the folder in addition to the contents of the folder.
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You can alternatively click on the Function Info button to get to the function edit screen
Then select a user from the Owner drop-down presented below and hit Save.
Information tab and change the owner from the displayed dropdown list:
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