From experience most people renew at a higher category of instructor rating, with the associated higher standard expected from the testing officer.
Depending who the ATO or FOI is will determine what you will have to do. Unortunately, standardisation in this industry is almost non-existent, and no two examiners will expect the same sequences from you.
Generally speaking, expect a long brief, preflight brief, and airex on the subject you did the preflight on, along with anything else the ATO requires.
You really need to be 'full bottle' on any sequences that you are allowed to teach as a G3.
If you have solo approval then you might be asked to assess the "student" on a sequence, and whether you would permit the student to go solo on that sequence or not. You would also be expected to justify your decision.
Good luck!
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JARSE! Pull and rotate 90 degrees