How to revert back from currency format, Android?

I'm developing Android app which uses this method:

public static String currencyFormat(BigDecimal n) {
    return NumberFormat.getCurrencyInstance().format(n);
}

which formats number based on Locale currency.

How to revert back from currency format, e.g. $35, to 35? Note that I cannot just remove First character because different locales have different currency name lengths.