How to differentiate add/remove lead to list request

Hi,

Am trying to add and remove lead from list using rest API (http://developers.marketo.com/rest-api/endpoint-reference/lead-database-endpoint-reference/#/Static_Lists )

Input request and api url are same for both add and remove API's.

Please find input request below,

{

  "input": [

    {

      "id": 0

    }

  ]

}

With this request am able to add lead to a list, but I also want to remove lead from list.

I need key parameter in input request which differentiate add and remove rest API.

Thanks.