How do I recan Number 10 cans of vegetables into smaller jars?
I would leave them as they are and use the canning jars to preserve other things like meats. Canning jars are too valuable. My time is also valuable. I don't do unnecessary things that add to my electric bill either. You can always figure out how to use all of the beans once you open them.
I am the mom of seven. I mostly buy #10 cans and can tell you from first-hand experience they will still be good many years after the "use by" date. I use my ears (vacuum seal), eyes, and nose to tell me if something is good or not.
After you open them, you can eat some fresh for a few days and also make and freeze a soup or casserole that uses them. You can dehydrate them or dehydrate and powder them (to bulk up sauces and add nutrition), etc. You could also can some after you used half the can, if you were so inclined.
To answer your question though: You would process them for the same times as stated on the USDA canning guidelines. To do less time could allow bacteria to grow. Since they have already been processed once, the texture may be affected. To have a copy of the guidelines in print at your disposal in these uncertain times, this book is only $14 (at the time I published this) and contains what you need to know: (#amazonaffiliate "As an Amazon Associate I earn from qualifying purchases.”)