Удаление копирайта IPB

Сабж. Как его удалить/изменить?(ipb 3.4.6) Способ с htmlOutput.php не работает, т.к. выпадает это:

Warning: Cannot modify header information - headers already sent by (output started at /home/example/domains/example.ru/public_html/example/sources/classes/output/formats/html/htmlOutput.php:1) in/home/example/domains/example.ru/public_html/noob/sources/classes/output/formats/html/htmlOutput.php on line 114

Warning: Cannot modify header information - headers already sent by (output started at /home/example/domains/example.ru/public_html/example/sources/classes/output/formats/html/htmlOutput.php:1) in/home/example/domains/example.ru/public_html/noob/sources/classes/output/formats/html/htmlOutput.php on line 127

Warning: Cannot modify header information - headers already sent by (output started at /home/example/domains/example.ru/public_html/example/sources/classes/output/formats/html/htmlOutput.php:1) in/home/example/domains/example.ru/public_html/noob/sources/classes/output/formats/html/htmlOutput.php on line 136

Warning: Cannot modify header information - headers already sent by (output started at /home/example/domains/example.ru/public_html/example/sources/classes/output/formats/html/htmlOutput.php:1) in/home/example/domains/example.ru/public_html/noob/sources/classes/output/formats/html/htmlOutput.php on line 137

Warning: Cannot modify header information - headers already sent by (output started at /home/example/domains/example.ru/public_html/example/sources/classes/output/formats/html/htmlOutput.php:1) in/home/example/domains/example.ru/public_html/noob/sources/classes/output/formats/html/htmlOutput.php on line 141