Easy, you take your tokens on a flash drive and fly to the Bahamas, where you meet in a back alley with Giancarlo and Paolo, who give you the keys from a dump truck full of unmarked twenties.
And there reverse is possible of course - you get the dollars to Giancarlo, end he gives you his IGUs (it's like IOUs, but without "O", because he officially doesn't "owe" you anything, as per terms of service). This is called "institutional investors".
It is fun to stay rich :)
