I use a pressure canner for those. In the past I've heard that some people use water bath, but that's guessing about the acidity of the tomatoes. Safer to pressure can. The Ball Book of Canning has good info.
Discussion
😲😲 water bath?
Do I have to use a pressure canner? I'm not gonna be selling them, just preserve them, as I love tomatoes, and I eat them like one eats chocolates, and I think the pressure canner you're talking about is a piece of steel that presses the fruit down so it remains submerged in liquid?