Unfortunately you can’t do it the way you are trying to. If your page was an HTML page you could just paste the revised code in the HTML page and try again.
But the code that the Validator checks is the final HTML output of the WordPress content management system. That code is generated from many places within WordPress, and you won’t even find some of it in the form you see it in the validator output anywhere in WordPress because the content you entered content is modified by PHP functions before the browser displays it.
When there are a lot of validator errors, cleaning up WordPress code can be time consuming. You have to find where in WordPress that code is generated from (make sure you’ve checked the View Source checkbox)
Places that are suspect are 1) page and post content from the WordPress editor, 2) text entered in widgets, 3) plugins, and 4) theme template files.
The good news with 106 errors is typically they cascade, which means because the browser interpreted one thing incorrectly, that one error creates other errors, which create other errors. When you locate a core underlying error, 20 or 30 errors can disappear from fixing that one.
The most common source of pages “looking screwy” is bad HTML – paragraphs and divs and LI or UL tags that are missing, or closed in the wrong order. When the # of opening and closing DIV or P tags doesn’t match, the browser often assigns a closing DIV to the wrong opening DIV, which breaks the page layout.
What I do with the validator’s HTML output is paste it into a text editor that highlights matching opening and closing tags. That is, a DIV at the top of a section should be matched with its closing DIV at the bottom of the section. If its matched with the wrong DIV I have to find the error and make the necessary corrections. If you don’t have an editor like that, a good free one is Notepad++
