My form has reached capacity but I need to edit a submission and it won

My form has reached capacity but I need to edit a submission and it won't allow me to do so - it just gives me the screen that tells me there's a waiting list.

How can you edit a submission without having to enable the form?

Forms will not accept new submissions is the form is disabled, this includes editing a submission.  If you need to edit a submission, you would need to temporarily enable the form.