[«SmG» Pandora]

1. Destroy all pillars as it heals the dragon.
2. Diamond gear is recommended, but you can also use iron gear. Make sure it's enchanted with the right enchantment such as Protection.
3. When the dragon flies back to the centre, attack its neck which deals the highest damage.
4. Avoid looking at every enderman you see walking around as they're extremely arrogant and will attack if you look at them.
5. Bring some golden apples or healing potions with you as you will gain some damage.

And if you want to take the dragon egg with you, surround it with a block and use a piston to push the egg. It will then be dropped as an item to pick up.