These are the the 2 ways you can edit your Json object.

jsonObj[name] = "Your name";

jsonObj.name = "Your name";

If you have array of objects you can use forloop to iterate and do same to update values.

for (var i = 0; i < jsonObj.length; i++) {
  if (jsonObj[i].Id === 3) {
    jsonObj[i].name = "Your name";
    break;
  }
}