A: Open <123livehelp_installation_DIR>/etc/, find livehelp_mysql_db.sql, to create a new database called livehelp in mysql db, you just need execute this sql file in command line.
Open <123livehelp_installation_DIR>/etc/lhserver.xml, find the "database-mode", and set the value to "mysql" as below,
<database-mode>mysql</database-mode>
Open <123livehelp_installation_DIR>/etc/mysql.xml, then configure this file with your own mysql db information. Save it and restart 123livehelp to make it valid.