If you did not update to 3.0.8 or 3.0.8.1 follow the instructions for 3.0.8. Otherwise:

Updating from 3.0.8 or 3.0.8.1.

1. Stop server
2. Take backup copies of your island worlds and the plugin folder just in case.
3. Copy this jar over the old one
4. To update language files, delete fr-FR.yml, hu-HU.yml and zh-CN.yml as they will be regenerated.
5. Start the server
6. You should be done! Report any bugs to GitHub.

Bug Fixes

• [Exploit] Player heads on an island could be turned into skulls by visitors placing an anvil on them.
• [Exploit] Heads could be taken out of the warp GUI by changing the language.
• [Exploit] Players could use anti-knockback cheats to still get into a locked island. Now they will be teleported to their island or spawn if they get too far in.
• [Medium] NPC's were being ejected from an island when it was locked.
• [Minor] Language file updates to Chinese, French and Hungarian.