How can you modifying due date for a required offering using HDL for mass learners

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I have over 2000 learners in a required course offering and I need to modify the due date. I see I can do it one at a time, but how can I do it using a dat file and the HDL? I'm still very new to Oracle systems and I'd really appreciate any help! 

I have attached the spreadsheet I used to create the dat to upload all my learners.

David