I did the exam recently - you have nothing to worry about. By this stage of your instructing career you should have a pretty good idea of the answer anyway.
Read the first six chapters of the FAA book. The exam goes back through what you learnt in your IP&M days.
The exam is not too hard, but some questions are very ambiguous. You will be given an example and be asked to state what defense mechanism, principle of learning etc. it was. So read all the examples they give you in the first 6 chapters.
Study but don't stress!
FTS