Coins can be left as is, revalued to the new dollar. New gold & silver coins can be minted to replace fiat currency. Blockchain (or similar) could replace electronic currency. All currency should be revalued to the gold standard, and fractional-reserve banking/derivatives/etc. must be 100% backed by gold equivalents.
All opportunities to manipulate the dollar's value must be ended or you know (((they))) will start doing it again.