Create a wtNode at '/Config/Settings/MiGS'
Create a wtConfig node at '/Config/Settings/MiGS/Merchant'. Give it a value of the MiGS merchant number.
Create a wtConfig node at '/Config/Settings/MiGS/Merchant Access Code'. Give it a value of the MiGS merchant access code.
Make sure '/Config/Settings/Orders/Payment Options/Credit Card' is set to 'Yes'
Make sure the option '/Config/Options/Payment Methods/Credit Card' exists.