Currently BuddyPress Media does not allow you to do that, but in case if its really that much needed, you can simply go to bp-media-loader.php, and you can change everything you want from this block :
/* Slug Constants */
define('BP_MEDIA_SLUG', 'media');
define('BP_MEDIA_UPLOAD_SLUG', 'upload');
define('BP_MEDIA_DELETE_SLUG', 'delete');
define('BP_MEDIA_IMAGES_SLUG', 'photos');
define('BP_MEDIA_IMAGES_ENTRY_SLUG', 'view');
define('BP_MEDIA_IMAGES_EDIT_SLUG', 'edit');
define('BP_MEDIA_VIDEOS_SLUG', 'videos');
define('BP_MEDIA_VIDEOS_ENTRY_SLUG', 'watch');
define('BP_MEDIA_VIDEOS_EDIT_SLUG', 'edit');
define('BP_MEDIA_AUDIO_SLUG', 'music');
define('BP_MEDIA_AUDIO_ENTRY_SLUG', 'listen');
define('BP_MEDIA_AUDIO_EDIT_SLUG', 'edit');
define('BP_MEDIA_ALBUMS_SLUG', 'albums');
define('BP_MEDIA_ALBUMS_ENTRY_SLUG', 'list');
define('BP_MEDIA_ALBUMS_EDIT_SLUG', 'edit');
/* Label Constants(need to be translatable) */
define('BP_MEDIA_LABEL', __('Media', 'bp-media'));
define('BP_MEDIA_LABEL_SINGULAR', __('Media', 'bp-media'));
define('BP_MEDIA_IMAGES_LABEL', __('Photos', 'bp-media'));
define('BP_MEDIA_IMAGES_LABEL_SINGULAR', __('Photo', 'bp-media'));
define('BP_MEDIA_VIDEOS_LABEL', __('Videos', 'bp-media'));
define('BP_MEDIA_VIDEOS_LABEL_SINGULAR', __('Video', 'bp-media'));
define('BP_MEDIA_AUDIO_LABEL', __('Music', 'bp-media'));
define('BP_MEDIA_AUDIO_LABEL_SINGULAR', __('Music', 'bp-media'));
define('BP_MEDIA_ALBUMS_LABEL', __('Albums', 'bp-media'));
define('BP_MEDIA_ALBUMS_LABEL_SINGULAR', __('Album', 'bp-media'));
define('BP_MEDIA_UPLOAD_LABEL', __('Upload', 'bp-media'));
Though I'll recommend you not to change anything as it will surely break the current permalinks of the media files you already have on your server and also it might produce some other bugs as well.