How do I assign the form to another account to manage?

If you would like to share the form to another account without removing it in your end, you can do that by following this guide: http://www.jotform.com/help/232-How-to-Share-Forms-with-a-Sub-Account-User.

You can also let them clone your form, here's the guide: http://www.jotform.com/help/42-How-to-Clone-an-Existing-Form-from-a-URL.

Or if you would like to transfer or move the whole form including the data on it to another account, we can do that in our end upon your request, just let us know what forms and to what account username you would like to move them. 

Thank you.