I want to use javascript to set attribute for selected element on webpage.

I have found 2 ways to set attribute using javascript

1

   WebDriver driver; // Assigned elsewhere

    JavascriptExecutor js = (JavascriptExecutor) driver;

    js.executeScript(document.getElementByID('//id of element').setAttribute('attr', '10'));

2

WebElement element = driver.findElement(By.id(foo));

    String contents = (String)((JavascriptExecutor)driver).executeScript(return arguments[0].innerHTML;, element);

But I want to apply javascript to specific webelement which i have found using selenium webdriver

as an example i have select one link using selenium webdriver

driver.findElement(By.linkText(Click ME))

Now I want to set attribute of this webelement using javascript

but I don't know how to combine both

please help me to find solution