edit footer

Hi David,
you can achieve that with this snippet:
http://presscustomizr.com/snippet/altering-adding-footer-credits/
or
https://ww.wp.xz.cn/support/topic/can-you-help-me-to-remove-the-footer-credits-1?replies=11#post-6616256

Hope this helps.

Change theme’s core files,
use that code in the themes’ functions.php.
Both these alternatives mean that you’ll lose your changed as soon you upgrade the theme.
One more alternative is about completely hide the central colophon block.