How to delete custom XSLT file from "User Type" edit detail page.

Hello Experts,

I want to delete the custom "Customer_USA.xslt" XSLT file in the "User Type" edit page as shown in the below screenshot of the "User Type" list page and want to restore the default XSLT file But when I open the edit page for User type "Customer_USA" to delete the "Customer_USA.xslt" file, I can't find "Customer_USA.xslt" file on the User Type edit page under "UI Design" section.

I checked "Branding" and "Responsive Template" sections under the "UI Design" menu.

I also notice that when I open the "Branding" section under "UI Design" there are search fields like "Right Logo Image", "Left Logo Image" and "Header Image" but when tried to add new Branding then I do not see these fields and just see 5 fields "Branding Name", "Default Brand", "Branding System Id", "Start Page" and "Responsive CSS File" no fields for Right, Left or Header images as shown in below image.

I really appreciate it if any expert guide or help me on how I can remove "Customer_USA.xslt" and restore the default UI Design for User Type "Customer_USA" and what setting I need to enable to see other fields while adding or editing Branding.

Thanks in advance for your guidance and help.

Krish