Unwrap, shaking off the plant material (this is best done outside in the garden if you have one).
Allow to dry, then press with a steam iron (use a pressing cloth). Allow to rest at least a few days before first rinsing.
The most difficult thing about this method is resisting opening the bundle to check on the colour!
Post-mordant in an iron-rich solution (or spray on using the hand-mister) and observe the colours change to olive greens and browns.