From Ground: Water the dorr's sage plant a couple of hours prior to the transplanting process, this would dampen the soil, making removal easier. Dig a wide trench around the plant using the spade or shovel, ensuring you don't damage the root ball. Proceed to gently work your spade or shovel underneath the root ball and slowly lift the plant out from the ground, preserving as many roots as possible.
From Pot: Water the dorr's sage an hour or two before you plan to transplant it, which would make removing it from the pot much easier. Once the soil is damp, tilt the pot on its side and gently pull the plant out, remember to not yank the plant out as this could damage the root ball.
From Seedling Tray: Gently loosen the soil around the plant using a small garden tool or even a fork. Pulling by the leaves, ever so gently, tease the seedling out ensuring minimum damage to the roots and the plant's stem.