[Plugin: Contact Form Clean and Simple] Resizing

Hey!

This is page from my website with contact form plugin:

https://kozlovskiy.com.ua/?page_id=184

I need to make it a little bit smaller. I’ve already read this topic:

<a href=”https://www.megnicholas.co.uk/articles/version-4-1-9-supports-bootstrap-3/
“>https://www.megnicholas.co.uk/articles/version-4-1-9-supports-bootstrap-3/

..but still don’t understand where I should past this code:

<div style="width: 600px;">[cscf-contact-form]</div>

Can somebody help me please?)