As the site neared completion my client declared that he wanted to be able to edit EVERYTHING on it. Obviously the simplest solution is to install an FTP on his computer but he is a self-proclaimed computer illiterate fool (he says it less politely than that!). He can barely send an email let-alone deal with html.
Is there a way to make the site editable through CMS or something so that the client, no matter how uneducated, can change content without encountering any web code? I'm an utter novice in this area so please reply as if I'm a stupid child!
Sorry to say this but you have to start from scratch because you are converting a complete static site to a dynamic site. Advantage you will be having is that you can increase the cost and cover the cost of static site that you have made.
See the thumb rule of development industry is that requirement changes price changes.
You have to make him understand this thing.
For your future reference: Before taking any project you should complete your documentation work because that plays a very important role in development industry.
In that documentation you can clearly specify requirement of client as well as costing for each thing.
This will help you to take obvious steps for development. One more thing if you are not making profit from this project then there is no need to complete this project. As no business can run with gaining loss.