Determine if a textbook is necessary to pass a class. Textbooks are not always the main focus of lectures, discussions or even assignments. Read over your syllabus to determine how much of your class work is based on textbook readings.
Visit your official class website. Professors often set up websites to accompany their classes. Always read class notes, presentations and other information related to discussions and lectures.
Identify the publisher of your textbook. Visit the publisher's website for the textbook's supplementary material. Often, publishers' websites will contain chapter summaries and quizzes.
Visit a library and check out the exact edition of your required textbook. Photocopy the relevant passages and return the book to the library when you're done. If local libraries don't have a particular text, ask to borrow a book from a classmate for a few hours. If photocopying is not an option, you can also scan or take digital photos of the book.
Attend all classes. Take exceptional notes. These notes can help take the place of the missing textbook.
Start a study group. Get together with your classmates and discuss the material. Share your notes with each other to ensure that you have a mastery of the material that has been discussed and assigned.