1. Remove foregrip.
2. Remove 3 screws holding gas tube/outer barrel assembly to body.
3. Slide gas assembly forward out of gun.
4. Grasp hop-up unit firmly, push toward the front of the assembly slightly, and twist 90 degrees (can't remember which way, but it will only turn one way)
5. Slide hop-up and inner barrel out of outer-barrel assembly.
6. Remove black plastic clip holding the barrel in (located infront of hop-up assembly)
7. CAREFULLY slide the barrel out of the hop-up.
"Someone in a Prius tried to race me at a stop sign the other day. I couldn't believe it. I had him for the first 100 feet or so but I can only walk so fast."