It's going to be a big job if they've been in place for many years--the roots get very large! You're doing it at the right time of year, anyway. Start by cleaning your digging/cutting implements, don't want to spread anything from other plants. I think it's easiest to start digging right around the outer edge of foliage, you'll probably have some feeder roots down pretty deep that far out. You'll just dig down around the whole thing, I'd start out at around 18" deep and use the shovel to wiggle the root ball once you've completed the circle. If it doesn't move easily you'll need to go deeper. Once you've established that digging ring you'll probably want to cut back the foliage to make it easier to handle. Once the root moves fairly easily you should be able to use the shovel to tip the whole plant and lift it out by reaching underneath and just manhandling it onto a flat surface. If it breaks while you're lifting it out don't panic, the roots are fairly brittle in the ground. I'm told they get a bit more flexible if you leave them sitting in the shade for a while, I've never been patient enough to try that....Use the garden hose to clean off the remaining dirt, you can normally see how the eyes are attached to the feeder roots then. You'll probably have to make a few cuts but most of the pieces should fairly much pry apart. Try to leave around 3-5 eyes attached to at least 1 or 2 good feeder roots/division. I've never stored peony roots for more than a few days, if you're doing more than that you'd probably want to put them in a pot or at least store them so they're not too wet yet don't completely dry out, either. There are several videos out there that give good demos, watch a few if you're not confident but normal herbaceous peony roots are pretty forgiving. Good luck!
