Remove parent categories from subcategory in URLs in 1.9.2.4

[Saegertown]

Magento version is 1.9.2.4.
I have tried following solution which doesn't work for me.
Step 1: Go to app/code/core/Mage/Catalog/Model/Url.php copy this file to app/code/local/Mage/Catalog/Model/Url.php because it is core Magento file so that we have to copy that file into the app/code/local.
Step 2: Now search for the getCategoryRequestPath($category, $parentPath) around line 698 in Magento ver. 1.9.2.4
Step 3: Search if (null === $parentPath) around line 717 and comment the line as below:

/* if (null === $parentPath) {
$parentPath = $this->getResource()->getCategoryParentPath($category);
}
elseif ($parentPath == '/'){*/
$parentPath = ''; //DO NOT Comment this line
//}

Step 4: Now Go to the Magento admin and Clear Cache System->Cache Management and Reindex System->Index Management the data.
Step 5: Refresh your browser cache and navigate again now you will see only the Sub Category in Url not the Parent Category just like as: http://www.cheapglasses.net/cheap-glasses.