Change the target attribute of a link from blank to self

Hi Ashish,

how xpath can be used here instead of id
js.executeScript("document.getElementById('//id of element').setAttribute('target', 'self');");
I need to change the target attribute of a link from blank to self so that the link opens in the same tab and then need to click on it
This is the element:
[code:2a8fasc0]WebElement element = driver.findElement(By.xpath("//a[contains(@href, '/athena/bir/download/export')]"));[/code:2a8fasc0]
i got something like this online
[code:2a8fasc0]WebDriver driver; // Assigned elsewhere
JavascriptExecutor js = (JavascriptExecutor) driver;
js.executeScript("document.getElementByID('//id of element').setAttribute('attr', '10')")[/code:2a8fasc0];
http://stackoverflow.com/questions/19934703/how-to-use-javascript-to-set-attribute-of-selected-web-element-using-selenium-we/19934852#19934852
but i am not able to implement this
plz help