How do I edit an SQL file?

[Charade]

The script I've installed is asking me to manually edit the database file, but my issue is that I don't know how to edit these codes. I've created an SQL database and uploaded the .sql file, but I couldn't edit the database file named db.php. What do I need to write in the places marked with ********* below? For example, the SQL database and username I've created are as follows:

$DATABASENAME = "************";
$CHANNEL = "**************";
$COMPUTERNAME = "***********";
$DB_USERNAME = "***********";
$DB_PASSWORD = "123456";

Can someone please tell me what I need to write where for the sake of someone's reward? I've tried everything but it didn't work