Halve the avocado and scoop out the flesh, discarding the stone. Zest and juice the lime. Add the avocado and lime to the blender with the coconut milk. Fill the can with cold water and add that. Blend till smooth.
Avocado a little firm? Pop it into a paper bag with the free banana we sent you and it should soften in a couple of days. You can add the banana to the smoothie too, for extra sweetness, but that will affect the nutritional information.