From Ground: Begin by
watering the area around the tiger lily to loosen the soil, this will make the extraction process less stressful for the plant. Using a gardening fork, gently loosen the soil around the plant's perimeter. Carefully work your shovel or trowel under the roots, and ensure you maintain a generous soil ball- this preserves the root system and increases transplanting success.
From Pot: Water the tiger lily sufficiently to ensure easy uprooting. Tip the pot sideways and softly tap the edges until the plant and soil slide out. Avoid yanking by the stem or leaves as it might damage the plant. Instead, gently tease out the roots if they're densely packed.
From Seedling Tray: Water the seedlings before transplanting. Gently hold the tiger lily by its leaves, not the stem, and use a dibber or narrow instrument to lift the seedling out, along with its roots.