You need to change the law if you want the central bank to move to a gold standard or to have a fixed monetary policy so that your legal tender currency doesn't inflate.
Other than that if you just want to trade using a non-inflatable currency you can just go right ahead and trade with gold if your counterparty accepts it. But if you're willing to accept that restriction something like bitcoin is probably a better solution that doesn't involve carrying and securing large quantities of heavy blocks of metal.
Other than that if you just want to trade using a non-inflatable currency you can just go right ahead and trade with gold if your counterparty accepts it. But if you're willing to accept that restriction something like bitcoin is probably a better solution that doesn't involve carrying and securing large quantities of heavy blocks of metal.