RemoveMovieClip or removeChild - how?

Question

I have an external swf that is loaded at frame 2 of the main timeline. The external swf has code that plays an flv, i've pasted the code below for the button that navigates the play head to the fram label 'frame2'.
I want to know, how can i unload the external swf after each button click? Does the code for unloading have to go to in the button code or the main timeline?
anim_mc.stop();
anim_mc.addEventListener(MouseEvent.MOUSE_OVER, onMouseOver);
anim_mc.addEventListener(MouseEvent.MOUSE_OUT, onMouseOut);
anim_mc.addEventListener(MouseEvent.CLICK, onClick);
anim_mc.buttonMode = true;
anim_mc.mouseChildren = false;
function onClick(e:MouseEvent):void
MovieClip(root).gotoAndStop("frame2");
function onMouseOver(e:MouseEvent):void
var mc:MovieClip = MovieClip(e.currentTarget);
mc.removeEventListener(Event.ENTER_FRAME, rewind);
mc.play();
mc.addEventListener(Event.ENTER_FRAME, advance);
function onMouseOut(e:MouseEvent):void
var mc:MovieClip = MovieClip(e.currentTarget);
mc.removeEventListener(Event.ENTER_FRAME, advance);
mc.prevFrame();
mc.addEventListener(Event.ENTER_FRAME, rewind);
function advance(e:Event):void
var mc:MovieClip = MovieClip(e.currentTarget);
if (mc.currentFrame == mc.totalFrames)
  mc.stop();
  mc.removeEventListener(Event.ENTER_FRAME, advance);
function rewind(e:Event):void
var mc:MovieClip = MovieClip(e.currentTarget);
if (mc.currentFrame == 1)
  mc.stop();
  mc.removeEventListener(Event.ENTER_FRAME, rewind);
else
  mc.prevFrame();
//my exteranl swf code.
var myLoader:Loader = new Loader();
addChild(myLoader);
var url:URLRequest = new URLRequest("external.swf");
myLoader.load(url);

Answer 1

I promise i'm doing what you told me and it still does not work.
I am doing what you tell me but there is something not right. (part of it is me, i know)
I placed this code into my physical movie clip that was created and is in my library. I gave this clip and instance name of 'night'
double click the 'night' clip and the following code resides on frame 1
////////////////////// now I'm assuming that the code below will create another movie clip within 'night' called 'myLoader3' , correct? So frame 1 of 'night' has
var myLoader3:Loader = new Loader();
addChild(myLoader3);
var url:URLRequest = new URLRequest("nightsky.swf");
myLoader3.Loader(url);
///////////////// i placed this code right below the code above, still in 'night' clip at frame 1
var src:String="daysky.swf"
daysky.addEventListener(Event.REMOVED_FROM_STAGE,f);
function f(e:Event):void{
MovieClip(e.target).loader.unloadAndStop();
//////////////////  now i'm a little confused by the above....does var src need to be the actual source of the swf? like var daysky.swf:String="daysky.swf"
///////////////// another question, i tried starting from scratch but no luck........sorry if i'm fustrating you.
I'm still getting "Access of undefined property daysky"