To convert from MySQL to MySQLi, just go to the site you want to convert and add a new MySQLi connection through the database panel. Once you have the connection made and working (test it with the test button). Then you can open any recordsets, insert, update, or delete server behaviors and change the connection from your old MySQL connection to the new MySQLi connection and the code should be updated for you.
Sorry I am new to this. I have downloaded and installed the Data Bridge package. I reopened dreamweaver. But what do you mean by the secondary installer?