The word "overhaul" comes from the nautical term for slackening a rope by pulling in the opposite direction.  This action allowed sailors to pull the rigging apart for thorough inspection and repair.  Over time, the term evolved to mean a thorough examination and repair of anything, not just ropes.  Today, it means to examine thoroughly and repair, renovate, or revise something completely, such as an engine or a system. 

According to the Oxford English Dictionary (OED), the word "overhaul" was first used in English in the early 1600s, with slightly different dates for the verb and the noun forms.  The earliest known use of the noun overhaul is from 1611, in the writing of R. Finch.  The earliest known use of the verb overhaul is from 1626, used by Captain John Smith in a nautical context, meaning to slacken ropes or dismantle rigging for inspection.  By the 1700s, the meaning extended to examining and repairing various equipment.   By the 1900s, it settled into its modern use for a "significant repair" or "revision," as seen in phrases like "overhauling an engine".  

Examples of "overhaul" used in a sentence: 
""Now the courts are forcing a thorough overhaul of that old order."  
"They had to overhaul their original plans due to the weather."
"Lawmakers are overhauling the welfare program and instituting new regulations."
"The county tore down the dilapidated factory a year ago to overhaul the space for updated commercial use." 
"The government said it wanted to overhaul the employment training scheme." 
"The study says there must be a complete overhaul of air traffic control systems." 

Just the facts:

OVERHAUL Definition & Meaning - Merriam-Webster

OVERHAUL Synonyms: 47 Similar and Opposite Words | Merriam-Webster Thesaurus