API PUT for updated custom type-ahead field

[MollieSh]

Hi can anyone help me with a PUT call to update user type-a-head custom fields I have this:

https://{mydomain}.sb01.workfront.com/attask/api/v14.0/project/636d27a6000349629ae8861e67f20e0d?upda...

{

    "DE:Custom User Field": 

[

    {

        "objCode":"USER",

        "name":"Test User",

        "ID":"5a949c86005796a9cb664d2130528750"

        }

    ]

}

}

And while we are at it, how about how to update a multi- select field via the API.  Thanks!