overhaul
n. countable C1 Advanced US //ˈoʊvɝˌhɔɫ// over·haul
n. a complete change or repair of a system or machine to make it work better. You use this when something needs more than just a small fix.
n. a thorough examination and repair of a system, machine, or organization to restore it to working order or improve its efficiency.
The company's website needs a major overhaul.
After years of declining performance, the school board decided to implement a complete overhaul of the curriculum.
The aging fleet underwent a comprehensive mechanical overhaul to ensure compliance with the new environmental regulations before the shipping season began.
From over- + haul.
Usage
Often paired with adjectives like 'major', 'complete', or 'radical'.