@wengriffin
Okay, here’s how to do it.
First, in the ‘wp-content/themes/parallelus-salutation’ folder make a new folder named ‘sensei’.
Now copy the ‘wp-content/plugins/woothemes-sensei/templates/single-lesson.php’ template into the ‘wp-content/themes/parallelus-salutation/sensei’ folder.
Next copy the ‘wp-content/plugins/woothemes-sensei/templates/single-course.php’ template into the ‘wp-content/themes/parallelus-salutation/sensei’ folder.
Now add the following code to the ‘wp-content/themes/parallelus-salutation/functions.php’ file…
$single_lesson_template = locate_template('sensei/single-lesson.php');
register_context( 'Single Lesson Pages', 'sensei_single_lesson', $single_lesson_template);
$single_course_template = locate_template('sensei/single-course.php');
register_context( 'Single Course Pages', 'sensei_single_course', $single_course_template);
Now in Appearance > Layouts you’ll be able to set a layout to use for Single Lesson pages and Single Course pages.
If you want to be able to set a layout for the related archive pages – i.e. the pages that list all lessons and all courses – repeat the same procedure with the ‘wp-content/plugins/woothemes-sensei/templates/archive-lesson.php’ and ‘wp-content/plugins/woothemes-sensei/templates/archive-course.php’ templates.
Don’t forget that each time you update the theme you’ll need to copy the ‘sensei’ folder into the updated theme folder.