[Guardian]

Not as complicated to install as it is to describe but here goes...

Slide the hop-up sleeve on the barrel making sure the little inside axial rib rides along the slot on the underside of the barrel. Push it in gently to avoid ripping the sleeve all the way. (The tapered end of the sleeve does not go over the barrel tube. i.e. you do not need to deform the sleeve. The sleave should not not cover the flat on the side on the barrel.) Apply a little silicone oil with your finger to lube the outside of the sleeve and slide it into the hop assembly. Drop the small nub into position in the square hole on top of the sleeve. Replace the hop-up rocker arm to capture the nub and insert the pin which holds the rocker arm in place. Slide the large collar over the barrel and into position against the hop-up assembly. There is an axial slot in the collar which allows it to fit past the front part of the assembly. You will have to deflect the small arm upwards a little so it pops into the radial slot in the collar. (This radial slot is tapered to a different height around the collar and is the reason you can adjust the hop-up) If you have done this all correctly the flat in the barrel which shows in the gap between the front and back of the assembly should be on the side. The final step is to drop the crown piece like a C-clamp into the gap trapping the collar. The crown piece will only fit if you maintained the correct barrel orientation. Looking through the barrel from back check that the hop-up grows as you turn the collar.

Good luck - I hope this helps.