Computer Science Homework Help

I need help on my part of the assignment, it just need to create modifications, extref, extdef. I attached the docx file below checkout all the instruction for my part are there highlighted in yellow, circled red on hand written. I attached the instruction file Pdf. Please follow the instructions let me know if there is something missing. I will be attaching my partners part once you accept the question! The book is attached bellow as well.

Please I need help to solve my part! It has to be done using C program