remodel, improve, reform

(かいぞう) Remodel a house or building.
(かいぜん) Improve a thing – your performance in Math class / the economy / the efficiency of the car
する(かいりょうする) Reform or improve
(かいぜん) Almost the same as 改良:to improve something – like new technology improves the productivity of the factory, but also like “If you don’t improve your grades, you can’t stay on the varsity football team, young man.”
(かいりょう) Almost the same as 改善 , but usually used only about technology, rather than social reform or personal betterment.
(へんこう) To change, but NOT to improve:to change the schedule of a meeting, or change a plan – (‘Instead of completing the building on January, we’ll finish it in March’)
(こうしん) Renew – a license or a library book.
める(あらためる) Change PLUS improvement. Usually used with behavior – meaning to turn over a new leaf, to quit self-destructive or bad behavior. Also has a totally unrelated meaning:When a customs official or police asks to see your ID card, that’s also 改める for some reason.
/(かいかく) Radical revolutionary change or total overhaul.
レフォーム Can mean re-modeling a building, but also means corporate re-structuring (i.e. firing people)
矯める(ためる) Fix or improve a system, correct a bad habit.