Instructions
Turn the slide over so that the bottom is facing upward, then insert the barrel into the slide so that the muzzle is flush with the front of the slide and the barrel lug faces away from the ejection port.
Compress the recoil spring lightly, then place it behind the barrel so that it engages the small cut-out slot in the barrel lug when you release the tension. Make sure that the spring does not pop out of place when you release the tension.
Hold the recoil spring assembly firmly with one hand and turn the slide over. Place the back of the slide onto the front rails of the pistol frame.
Pull the slide all the way back on the frame as far as it will go, then gently ease it back to the "closed" position.