How to Make M4 CQBR Out of M4 (Airsoft)

One day I went airsofting with my AK-74U(Because my MK.18 Mod 1was too big). And on my way home I thought, since there is no M4 CQBR, why don't I make one by myself. So I went to market, bought myself a Colt M4 and start making it. 
Anyway here is what u need for making M4 CQBR
1-Airsoft Colt M4
1-Duct Tape
1-Office Knife
1-Lighter
1-Super Glue
1-Saw
1or 2-Rail
1-Sand Paper

Before u get into sawing and gluing measure the length of the barrel. Since there is inner barrel I measured it with pencil.

If u r done with that mark the place where u are gonna saw.

If u r done with that Saw it.....

After u r done with sawing it should look like this.

Now pick up the barrel that u sawed off and mark the place where u will cut(because u need flash hider).

Now saw it....

The flash hider should look like this after u sawed it off.

Now with sand paper soften the sawed part of flash hider and the gun.

Now attach the flash hider to your gun with super glue and duct tape.

Now your M4 CQBR is finished. Now go out and get 'em Private!