How to change Schema?

Hello,
I want to change schema, I saw that you give a code to change schema but question where to add it. Should I edit function.php or change any plugin file?

And srcond thing is that how to show stars in one line. I want this kind of thing.

Example:
Hello this is site – (Stars)

Dont want this:
Hello this is site –
(Stars)

I am using this code:
<?php if(function_exists('the_ratings')) { the_ratings(); } ?>

Can you help me with it.

https://ww.wp.xz.cn/plugins/wp-postratings/