1. You can make the changes yourself and charge the customer for it. 2. You can explain the importance of On page SEO and recommendations. I wouldn't recommend working with a client who is adamant on hurting themselves !
SEO Campaign Implementation Involves : Coding the website (X)HTML templates in a search engine friendly format Developing an external Cascading Style Sheet Accessibility testing Usability testing Writing effective Title and Description Meta data Optimising site navigation Setting up site maps, error pages and robots instruction documents Eliminating server-side issues Optimising dynamic content Optimising web page copy and contents