To clarify any details means to make things more clear and understandable by providing further explanations or answers to any questions or doubts. Full definition
Whether you have a question, or want to clarify some details of the project, you can simply write your writer and discuss the matter directly with him. (paperwritingservice.info)
You may clarify all details about fees and payment options in your initial meeting. (goodtherapy.org)
Thanks for clarifying the details for the giveaway — glad to hear it's a random draw! (stylebee.ca)