Change MySQL master to a slave

I have a MySQL master/slave configuration

 --------        --------  
| master |  ->  | slave1 |
 --------        --------  

I want to kill my current master, transform slave1 to be the new master and have another slave pointing to slave1

 --------          ------------        --------
| master |        | new master |  ->  | slave2 |
 --------          ------------        --------
  KILLED

What is the best way to do this without database downtime? I am using MariaDB 10.0.17