If you want to get high rankings then change your web pages
If you want to get high rankings for certain keywords, then these keywords must appear on your web pages. It is possible to get high rankings for a keyword that is not listed on your website if lots of other websites link to your website with that keyword. That’s the exception, though. In general, the keywords for which you want to be found must appear on your web pages and they must appear in the right elements on your web pages. For that reason, you have to change the HTML code of your web pages to make it as easy as possible for search engine spiders to parse your site.