Your hardest task will be to find turtle meat. My first advice would be to cruise the Asian markets in your town, if you have any. Or, if you have the funds, you can actually buy wild snapping turtle meat online. It'll cost you, but the tub of meat is enough for several meals. More likely, however, you will be substituting. Alligator is the closest thing to turtle in my experience, and frog legs come pretty close, too. Barring those options, I might use a combination of chicken thighs, pork shoulder and clams. (I've never done it, so you'd have to come up with your own ratio.) You can skip the clams if you think that's too weird, but remember that turtle does have a seafoody taste. Once you've cleared the meat hurdle, everything else is easy.