Strawberries have small, shallow root systems usually. When I have a bunch of established runners that take over a bed, I will trowel a circle around the plant about 3-4 inches around and 4 inches deep. A gentle lift/tease out of the ground and voila!
Ideally, spring/fall time is the best to transplant but I think you will still have success at other times. Just be gentle and pamper the plants in their new locations.
