Complete your initial ACT test and receive your score.
Determine where you need improvement. Since the point of taking the ACT multiple times is to improve your score, you need to study the areas where you can improve. For example, if your math scores are high, but language scores low, you know you need to focus more study time on the language section.
Study for your next test. Private tutors or classes that focus on the ACT can help you improve your score.
Register for the ACT. Registration for those retaking the test is the same as for those taking the test the first time. You can register online through the ACT website or you can mail in a paper application.
Take the test on the date for which you registered.
Repeat this process if you still need to improve your scores.