Thank you so much. For anyone that comes after me with this question, this is the solution:
=OriginalTrainerName=NewName
.TrainerTID7=12345
.TrainerSID7=12345
I tried the example codes .trainerTID7 and .trainer SID7, taking trainer out, taking T out of TID, doing just TID and SID etc.
Did the code change or am I doing something wrong?