Customizing Membership signup page

Hello and good afternoon,
I have a question. I need to adjust the current sign up page for Memberships pro but for only a few sections. An example can be seen below in the image. I created and added the custom css field to my template thirdparty.css file however, I am unsure where to put it. Changes I want to make are as follows:

Change Custom field containers from control-group payment_information to control-group2
Could you help direct me as to where I can make this change?

Thank you,
Sarr
https://gyazo.com/a52dee2b800de48d54d4691c3086c534

Hi

You want to change from control-group to control-group2 for all fields for just for some specific files? In short, the file you will have to make changes is components/com_osmembership/view/register/tmpl/default.php or components/com_osmembership/view/register/tmpl/default_form.php if you are using latest version of the extension

I see that you made many changes to the form layout, so maybe you know it already?

Tuan