change url seo searchterm tagging 2

I need to know that how to change seo searchterm tagging 2 wordpress plugin permalink structure from domain/search/search-term/ to domain/anything-else/search-term/

please tell me i tried editing in plugin and i have changed link structure plugin start showing my new structure but when i open link it gives error 404 not found.

i changed this
PHP Code:
$permalink = get_bloginfo( 'url' ).'/search/'.user_trailingslashit(pk_stt2_function_sanitize_search_link($term->meta_value));
to
PHP Code:
$permalink = get_bloginfo( 'url' ).'/myword/'.user_trailingslashit(pk_stt2_function_sanitize_search_link($term->meta_value));
and this line
PHP Code:
$new_rules = array('^search/(.+)\$' => 'index.php?s=' .$wp_rewrite->preg_index(1));
to
PHP Code:
$new_rules = array('^myword/(.+)\$' => 'index.php?s=' .$wp_rewrite->preg_index(1));
but no success it make url like https://mydomain.com/myword/search-term/ but gives error 404 not found.

please help me if you know how to change it.
i need it because i am using AA 404 plugin on search page for related content and while /search/ comes in url it always gives same posts which have word “search”
so i want to change /search/ to something else which didn’t disturb AA 404 plugin.
thank you