Delete attribute from custom Type

[#1]

Hello,

I have a custom Type that has an attribute that references another Type by mistake.  I have tried to delete this attribute using a PUT api call to: /api/atlas/v2/types/typedefs
But got the error:
ATLAS-400-00-00D: attribute delete not supported.
I even tried to to update the attribute to not longer reference the Type but instead have "typeName": "string", but I get the error:
ATLAS-400-00-029: Data type update for attribute is not supported

Is there a way to delete an attribute from a custom Type?