Add section to update the root password, so that recovery can take place

recover_innodb_cluster.md

@@ -47,6 +47,31 @@ mysql-innodb-cluster/2*  active    idle   2/lxd/6  10.0.1.156
 
     Check the mysql status: `sudo systemctl status mysql`
 
+1. A temporary password would have been created via the `--initialize` above, so this needs to be updated.
+   You will find the temporary password in `/var/log/mysql/error.log`, and the line should look similar to the one below
+
+   ```
+   [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: wyPd_?kEd03p
+   ```
+
+   First we need to get the root password that is stored
+
+   ```
+   juju run --unit mysql-innodb-cluster/leader 'leader-get mysql.passwd'
+   ```
+
+   Now, we can update the password, login using the password that was suggested in the error.log i.e. `wyPd_?kEd03p`
+
+   ```
+   mysql -p -u root
+   ```
+
+   Once logged in, we can update the password to the value that mysql-innodb-cluster charm knows about
+
+   ```
+   ALTER USER 'root'@'localhost' IDENTIFIED BY 'zn8K73dmqnkZd99JZxXwcFmxWqTxPYgw3Hjx5sk';
+   ```
+
 1. Remove the flags using Juju:
 
    Clear flags to force charm to re-create cluster users