URGENT: general questions for registering O-level Eng language as a private candidate

Hi everyone,
I'm from Hong Kong and I'm currently taking IB English A2 Standard Level, and I'll be taking my IB exams in this coming November.
However, I'm worried about my grades in this subject. It has been extremely volatile: sometimes I did well but sometimes it did bad.
So, to insure myself that if I really stuffed up my November English exams, I would like to register for GCE O-level English language in January.

So, I would like to ask for advices as to how I should start registering? (e.g. what modules/options I should enroll in?)

Thanks :yep: