Yes, the leader can be changed.

If you want to change the Alliance leader, you should promote an Alliance Member to Rank 5. 

When changed, the current leader will fall to Rank 4 and the promoted member will become the leader

.

■ How to Change the Alliance Leader

- [Main Screen] > [Alliance Ensign] > [Members] > [Select R4 Alliance Member] > [Promote]

■ If the Leader is Absent

If the leader has not logged in for 7 days or more, R5 promotion authority is given to Rank 4 members. 

The Rank 4 members can choose one member to replace the Alliance leader.