Customize via PHP

I was wondering if there was an easy way to get the “remember me” box and text to be where the “don’t have an account” text is, and also how to delete the “don’t have an account” text since I am using a different widget to handle registration. I thought I figured it out by going into and changing the php file, but when I updated the file, it doesn’t change at all. Anyone have any ideas?

https://www.ads-software.com/plugins/nice-login-register-widget/