Sections on CodeHS can be co-taught by multiple teachers. Once you've created the class from your Teacher page, visit the Section Settings page by clicking on the gear icon in the top right corner of the page.
From that page you will find instructions on how to add a second (or third) teacher to your section. Once they have been added to your section, both teachers will have the same viewing, grading and administrative privileges over the section.
If you would like to remove a co-teacher please contact firstname.lastname@example.org.