If he has a good lawyer, he should be able to convince the court to (i) discount the $155k due to current market conditions and employability of that job title, (ii) consider the fact he has not worked in that job for a while and may have to take a step down salary wise to get back in, and (iii) wait until he finds a job before setting support and award his request for a reduction until then. He can also ask the court to impute your new expected income as a benefit from your schooling, which would adjust down your prior support level anyway.

DISCLAIMER: The above ramblings do not constitute legal advice of any kind and are not intended to solicit or imply any kind of attorney-client relationship or legal service rendered.