If i have a one year old website withe some daily unique visitors. I want to hire some seo person for its seo and he makes bit changes on site for on page seo. And if site is internally linked wrong then he will make changes in those sections too. So the site ranking comes down first and it is also chances that it faces google panality. So what you people suggest handing a new site to seo person is good or just make another website and handover this to him. As i my self is developer so making new website is not problem at all.