If you would like to change your course, here is a sample application later for a change of course in University. You can also use this template to write an application for change of course letter.
I am [Name], a student of your university pursuing [Course Name]. I am writing this letter to take your permission for a course change.
I would like to take a transfer from [Old Course Name] to [New Course Name]. The reason why I have made my mind to change the course is [Mention your reasons]. I request you to allow me to do the same.
I understand transfer/change from one course to another can be difficult, but this is really important for me. I will be highly obliged to you for the same.
For your reference, I have attached my course details and registration documents. I look forward to hearing from you.