Dig Divide and Transplant Hostas
Gardeners find some very creative ways to get a job done. Several have told me using a bulb planter worked for them. They position it over the crown and apply enough pressure to cut through the roots. If you opt for this method, I would recommend trying it on one of your less expensive hostas.
I prefer a shovel to dig and a linoleum knife to cut the plant into several divisions. You can divide the plant in half, fourths or eighths, depending on its size and how quickly you would like the division to fill its new spot.
No matter how you dig and divide, amend the soil before planting the divisions in the same or new locations and water often enough to keep the soil slightly moist.
A bit more information: Amend the original and new planting locations with organic matter. Incorporate compost, peat moss or aged manure into the existing soil to improve drainage and increase water holding ability. Mulch with shredded leaves, evergreen needles or other organic matter to encourage root growth.