In the fall, a few weeks before first frost ease off watering and let the tree experience some dips in temperature including light frosts. Leaves should yellow and fall off.
Right before storing the tree, spray it with dormant oil. This will kill off any pests.
When frosts are near, move the container to a garage (ideal temperature range is 0-10°C / 32 to 50° F).
Keep the plant in darkness (I put a big bag over mine).
Some people don’t water them at all. I water mine very lightly every 6 weeks or so if the soil is really dry (a sign it needs new soil).
Spring
A few weeks before last frost, start watering the plant again and gradually reintroduce it to sunlight.
Two weeks or so before last frost, place the tree outside, ideally in a warm spot. I put mine next to an exterior brick wall with southern exposure.
If you’re still having frosty nights, bring the tree inside at night or cover it with heavy row covers or frost cloths.
Within a few weeks you will see new growth, sprouts, and leaves.