curl -k -X PUT -H "Content-Type:application/json" -H "Accept: application/json" -d '{"id":"asdfg","UserID":"asdfg","Password":"foobarfoobar","FullName":"newFullName","Link":{"rel":"self","href":"https://localhost.localdomain:8443/ca/rest/admin/users/qwerty","type":"application/xml"},"Attributes":{"Attribute":[]}}' --user caadmin:Secret.123 -s https://localhost.localdomain:8443/ca/rest/admin/users/asdfg | python -m json.tool
{
    "id": "asdfg",
    "UserID": "asdfg",
    "FullName": "newFullName",
    "Link": {
        "rel": "self",
        "href": "https://localhost.localdomain:8443/ca/rest/admin/users/asdfg",
        "type": "application/xml"
    },
    "Attributes": {
        "Attribute": []
    }
}