Get a new instructor, at a different school.
Why is it always the Instructor at fault? Perhaps its the student with an inflated idea of being about to go solo based on internet forums telling him that as he has enoug hours he may be ready?
It could well be that he is nowhere near going solo (even if he is being told he is about ready to boost confidence) and that the Instructor is still in teaching and follow through mode?
Lets face it, if the student does not even know how the nose wheel works on a 152 are they anywhere near ready for solo.....