Many students find themselves on the wrong course and want to change. If this applies to you, be very sure that you do want to change and that you know what course you really want to do. There is no automatic right to change course and you may find yourself unable to because there is no place on your preferred course or you do not have the entry requirements for it.
It is harder to make a change the longer you stay on a course. If you change within the first two weeks of starting your course, you may be able to start more or less seamlessly on another. However, if you leave it until later into your first year, or even your second year, it is likely that you will have to start your new course from scratch.
Speak to your Personal Tutor, the Senior Tutor, and/or the Student Advice Centre before you make a decision. They will be able to advise you of the academic, personal and financial implications of changing course. Discuss it with family and friends.
Once you have made a decision, you can approach the department or other University to see if there is a place for you on your chosen course and how and when you should apply. Another University might ask you to apply through the UCAS process. Your present department will have to agree to the transfer.
Discuss the matter of fees and student funding with the Student Advice Centre. You may not be completely funded on your new course, depending on when you transfer.