How do I find a line number in the wp-includes/classes.php file?

I am trying to alphabetize my categories on the right-hand side of my blog. I found this on the helps:

I finally figured out how to hack the categories to display in alphabetical order for wordpress 1.5. You modify the wp-includes/classes.php file. Go to line 462, and add in this:

// Alphabetical hack for categories
if ($whichcat)
{
$q[‘orderby’] = ‘title’;
$q[‘order’] = ‘ASC’;
}

How do I find line 462? They are not numbered.

Thanks. Jeanne