The armature is the little pin that goes into the solenoid housing. You need to remove the bracket to get the armature out. Leaver the bracket off with a flat headed screw driver. **make sure you do not damage the coil around the housing when doing this**
Its probably a bit of crap inside the housing or sat on the face of the armature.
Basically involves opened up the grips and using a combination of the programming button, trigger and power button to change the dwell. Explains on that site though. If you have trouble just post here and someone will help.