DBの文字コードの変更方法

[root@localhost ~]# mv /etc/my.cnf /etc/my.cnf.bk
[root@localhost ~]# vi /var/lib/mysql/my.cnf
[root@localhost ~]# service mysqld restart

my.cnfを編集する際に以下の文章をそのままうちこみます

[client] 
port = 3306
socket = /var/lib/mysql/mysql.sock

[mysqld] 
port = 3306
socket = /var/lib/mysql/mysql.sock
key_buffer = 64M
max_allowed_packet = 16M
table_cache = 2048 
sort_buffer_size = 1M
read_buffer_size = 1M
read_rnd_buffer_size = 1M
myisam_sort_buffer_size = 1M
thread_cache_size = 8
query_cache_size = 0
max_connections = 50
thread_concurrency = 8
log_error = /var/lib/mysql/mysql.err
log-bin = /var/lib/mysql/mysql-bin
binlog_format = mixed
expire_logs_days = 3
server-id = 1
slow_query_log
slow_query_log_file = /var/lib/mysql/mysql-slow.log
log_output = FILE
long_query_time = 1
character-set-server = utf8
skip-character-set-client-handshake
# innodb innodb_buffer_pool_size = 256M
innodb_log_buffer_size = 16M
innodb_flush_log_at_trx_commit = 1
innodb_lock_wait_timeout = 5
innodb_file_format = Barracuda
innodb_flush_method = O_DIRECT
innodb_read_io_threads = 4
innodb_write_io_threads = 4
innodb_file_per_table
skip_innodb_doublewrite

[mysqldump]
quick max_allowed_packet = 16M