Trello REST API - CheckItem due dates

How can we access these values and change them from the API?

You can see the duedates of your checklist items by calling the
GET /1/cards/{id}/checkItem/{idCheckItem}. The due dates should be a datetime value under the due field.
You can update a duedate of a checkitem using the following API call:
PUT /1/cards/{idCard}/checklist/{idChecklist}/checkItem/{idCheckItem}
and have the due field with an appropriate datetime in the body of the request.
Here is a link to the documentation: