Can I change the question type after a survey has been shared

My team mate created a question that asks participants to choose up to 8 options, but made it a single selection question and shared. How can I change this without having to create a new question lose capture of the original submission.

I have inspected your form and I saw that you have two fields with same options, one is radio button and other is check box field. Unfortunately it is not possible to change the type of fields. 

If you do not need radio button field you can simply hide it.

Other way is to edit your previous submissions and populate your new check box field with data that was selected in radio button field. After you update all your submissions you can delete radio button field.

How to Edit Submissions Made on Your Forms

Hope this will help. Let us know if you need further assistance.