Copy whole local storage to import it somewhere else.

replaceStorage.js

const replaceStorage = doubleStringifiedStorage => {
  // copy storage with `copy(JSON.stringify(JSON.stringify(window.localStorage)))`
  window.localStorage.clear()
  const imported = JSON.parse(doubleStringifiedStorage)
  for (const n in imported) {
    localStorage.setItem(n, imported[n])
  }
}