Of course, as Sophia said, you need examples, but in general, 3^rd persons do not change and first and second do. So, �she said: �I won�t go� becomes  �she said she wouldn�t go� but �she said: �she won�t go� still is  �she said she wouldn�t go�. If you know because of the context that the �I� is still �I�, say for example, the listener did not hear properly or you want to remind somebody of something you said, you could still use �I�: � I said I wouldn�t  go�. In sentences with no context change is usually expected.

Best wishes