Transitioning from a demo to a live account when trading Forex is a reasonably simple procedure. Depending on your broker, funding an account and starting live trading could be as simple as clicking on a webpage. In the end, most brokers want you to trade live, and the demo is the first step in the process of signing up a new client.
One of the most important things to note is that the trade of a live Forex account is at least psychologically very different from a demo account. After all, you're losing money now, and it's much worse than a trading mistake. If on a demo account you make a mistake, you're only dealing with your pride, whereas in a live account, your pride and money are at stake.