You are free to remove credit links to PreMadeNiches, PMThemes or other footer links to any sites. Feel free to change it to your own links if you wish.
To edit or remove footer credit links just login to your WordPress admin then navigate to Appearance => Customize => Theme Settings => Footer Settings.
To delete the link, just highlight all HTML contents of the “Footer Text” field then hit “Delete” button on your keypad.
If the “Display credit link to pmthemes on footer.” is active, just uncheck it.
To change credit link to your own links, edit the HTML code directly or simply copy and paste your own HTML code into the text box.