Making minimal modification to JSON data without a structure in golang

I have a solr response in JSON format which looks like this:

 {
  "responseHeader": {
    "status": 0,
    "QTime": 0,
    "params": {
      "q": "solo",
      "wt": "json"
    }
  },
  "response": {
    "numFound": 2,
    "start": 0,
    "docs": [
      {
          <Large nested JSON element>
      },
      {
          <Large nested JSON element>
      }
    ]
  }
}

Now, in my Golang app, I would like to quickly remove the "responseHeader" so that I can return the "response" alone. How can I do this without creating large structures?

Edit 1

The answer by evanmcdonnal was the solution to this problem, but it had some minor typos, this is what I ended up using:

var temp map[string]interface{}

if err := json.Unmarshal(body, &temp); err != nil {
    panic(err.Error())
}

result, err := json.Marshal(temp["response"])

Here's a really brief example of how to do this quickly and easily. The steps are; unmarshal into the universal map[string]interface{} then, assuming no errors, marshal only the inner object which you want.

var temp := &map[string]interface{}

if err := json.Unmarshal(input, temp); err != nil {
     return err;
}

return json.Marshal(temp["response"])

I wrote a package µjson to do exactly that: performing generic transformations on JSON documents without unmarshalling them.

Run on Go Playground

input := []byte(`
{
  "responseHeader": {
    "status": 0,
    "QTime": 0,
    "params": {
      "q": "solo",
      "wt": "json"
    }
  },
  "response": {
    "numFound": 2,
    "start": 0,
    "docs": [
      { "name": "foo" },
      { "name": "bar" }
    ]
  }
}`)

blacklistFields := [][]byte{
	[]byte(`"responseHeader"`), // note the quotes
}
b := make([]byte, 0, 1024)
err := ujson.Walk(input, func(_ int, key, value []byte) bool {
	for _, blacklist := range blacklistFields {
		if bytes.Equal(key, blacklist) {
			// remove the key and value from the output
			return false
		}
	}

	// write to output
	if len(b) != 0 && ujson.ShouldAddComma(value, b[len(b)-1]) {
		b = append(b, ',')
	}
	if len(key) > 0 {
		b = append(b, key...)
		b = append(b, ':')
	}
	b = append(b, value...)
	return true
})
if err != nil {
	panic(err)
}
fmt.Printf("%s", b)
// Output: {"response":{"numFound":2,"start":0,"docs":[{"name":"foo"},{"name":"bar"}]}}

You can read more about it on the blog post. I put the answer here just in case someone else might need it.