From Ground: Begin by watering the soil around your giant red Indian paintbrush to make the soil easier to dig and reduce the stress on the plant. Using a shovel, dig around and under the plant aiming to keep the root ball intact. Gently lift the plant from the ground and try to retain as much of the root and the surrounding soil as possible.
From Pot: Water the giant red Indian paintbrush more than usual until you see water coming out of the bottom. Turn the pot on its side or upside down and gently tap on all sides until your giant red Indian paintbrush slides out, again, be careful not to disturb the root ball.
From Seedling Tray: Moisten the soil of your seedling tray for easy removal. Use a narrow implement like a dibber or even a pencil to push up the soil from the bottom of the cells or slots until the giant red Indian paintbrush comes out. Ensure you support the root during this process so as to prevent damage.