change over

(noun) an event that results in a transformation. Synonyms: conversion, transition, changeover.

(verb) make a shift in or exchange of. Synonyms: switch, change over, shift. Example: "First joe led; then we switched."

(verb) change from one system to another or to a new plan or policy. Synonyms: convert, change over. Example: "We converted from 220 to 110 volt."