Hello,

You should contact the head of your school regarding this, as they will be able to guide you better in terms of possibility of changing stream, but prior to that make sure you're doing something with clarity in mind, what I meant is do you have any interest in BiPC stream, or you're finding some topics tough to comprehend, in that case you can always ask your teacher, in case you feel like you want to go ahead with MPC stream, then talk to your school authorities, if such a process is probable or not.