laws and start circulating gold and silver coin.
The gold and silver will eventually push the "price" of paper currency so far out that people will stop using it fast.
No need to set any exchange ratio or anything.
Just mint real coins either with the old dollar standard of 371.25 grains .999 pure or mint .999 pure coins in grams or fractions of troy ounces and don't stamp any denomination on them.
Either way - it's quick, easy, and the least painful method - and all free market.