How to safely change MySQL innodb variable ‘innodb_log_file_size’?

http://dba.stackexchange.com/questions/1261/how-to-safely-change-mysql-innodb-variable-innodb-log-file-size

innodb_log_file_size = 25% * innodb_buffer_pool_size, np:

[mysqld]
innodb_log_file_size = 64M