Let’s say you have access to power and authority under the current system. You also have a considerable amount of wealth yourself or access to wealth. This is a two phase process.
First, you initiate a fiat currency system in society and everyone is convinced that this system is workable and they accept the currency as a medium of trade. You begin your process by implementing this system in society. For a few years all is well and the currency is accepted in commerce. Now you begin to print more and more currency so you can buy up hard assets. This is debasing the currency to benefit your plan. The sellers willingly sell to you because of their confidence in the currency. You pay for their assets with worthless paper, only valued by perception. Once you have bought up their assets, you now need to protect yourself from losing those assets by someone else with more of the fiat currency. It is now time to change the rules and convert to a sound currency.
You revert back to a gold-backed system of payments and only those who have gold can buy assets back. Since you have been acquiring gold with fiat currency, you can protect yourself from others attempting to take your assets from you with your low cost gold. Those left holding the fiat currency end up with nothing but memories. What a plan!