[NTG-context] Transition from ConTeXt mark II to mark IV

Hallo. I need some help. I have all my teaching materials (slides, worksheets, and everything, including many MetaPost figures) in ConTeXt mark II. After the transition to Ubuntu 24.10, I found that the texexec is not a part of the ConTeXt distribution anymore. I tried to compile my stuff with context instead and failed. This is probably because the macros in my old modules (created by myself many years ago) are not compatible with mark IV. Hence my question: Is there any document on the transition from mark II to mark IV? Many thanks for your kind help. Best wishes, Michal