The Smith Shop Whisper Springs Kit Instructions

Spring Kit Install
Similar for 1860/1866/1873 Rifles
1. Disassemble the rifle to this point.
2. This picture shows the Whisper Spring generally in place. However, it is most difficult to get the screw started in this position. What needs to be done is to make some room for the "nut" part of the Spring assembly to be able to start the screw without pressure on it. 
3. Set the Whisper Spring aside for now and with your finger push the carrier upward. Continue upward until the carrier is at the top of its stroke. This action may cause the lever to also "open" if it already isn't. That's fine.
4. Now we have room for the Whisper Spring Nut to be aligned with the screw without any pressure on it. So insert the screw into the hole and align the Whisper Spring Nut over the screw, but with the Whisper Spring leg sticking out the side of the frame.
5. Now catch a couple of threads of the screw in the nut. 
6. Swing the Whisper Spring leg into place onto the lever (or lifter when doing that side).
7. Using a finger to apply some downward pressure and to hold the Whisper Spring leg onto the cam surface, draw the Whisper Spring nut down with the screw. 
8. Tighten the screw all the way. The carrier can now drop down alongside the Whisper Spring nut. 
9. Be sure the Whisper Spring leg rides the cam all the way in both directions and does not slip off. A light tap on the nut with a drift will help align the nut if necessary. 
The short leg can also be bent downward to give more torsion to the spring. 
10. Do the same for the lifter assembly.