If you need to disable Relevanssi, for example for a particular template, all you need to do is to unhook two filters:
remove_filter( 'posts_request', 'relevanssi_prevent_default_request' ); remove_filter( 'posts_pre_query', 'relevanssi_query', 99 );
Before versions 4.10.2 (free) and 2.12.2 (Premium), you need to unhook these filters:
remove_filter( 'posts_request', 'relevanssi_prevent_default_request' ); remove_filter( 'the_posts', 'relevanssi_query', 99 );