FirefoxProfile profile = new FirefoxProfile();
// OR
// FirefoxProfile profile = new FirefoxProfile(new File(...));
// Init your profile
// OR
// If you created the profile by providing a path to it,
// the path should refer to the one on the host of the WD server
DesiredCapabilities caps = DesiredCapabilities.firefox();
caps.setCapability(FirefoxDriver.PROFILE, profile);
WebDriver driver = new RemoteWebDriver(new URL("http://<....>:4444/wd/hub"), caps);