I am now doing my exam about how Lady Macbeth has changed?

The exam is in three weeks. The exam question is" How did Shakespeare present L. Macbeth in Act 1 Scene 5 to Act 5 Scene 1." If any of you guys did this exam , could you give me some tips and targets. The requirements of the exam is 2000 words? Please include your previous experiences of the test and how did you get the mark you did in the test?