use this plugin in another format (DW question answer)

This plugin is really great.
I want to use this plugin in another format (DW question answer).
You can use this nice plugin in other formats by adding “add_filter ('bp_docs_wp_editor_args','hm_bbpiu_modify_editor', 9999); in a previous question.
But don’t know where to add it?
Please tell me where to add.