Built a site on Nirvana years ago for a musician, and he’s been very happy. He’d like to make some updates to the site now. But when I logged in to take a look, all the old Nirvana editing controls are gone. I’ve read the docs about using Customize and setting a home page, which makes sense, but I’m afraid if I do that I’ll ozone the old page, which is still 80 percent the way he wants it. I’ve saved the code separately into a new page, but obviously that’s a mess. How do I transition his site?