The usual method of eliminating oscillation (and that is the goal - eliminating, not reducing as you say) is to tweak the power supply rails. More often than not involves better power bypassing. Then you need to worry about the supply voltage, and if it still won't work right, look at the gain you're asking the opamp to do, and finally look at the impedance of the load... maybe the opamp just isn't suited for it!
I should add that there is usually ZERO audible benefit to improving power bypassing if the opamp isn't oscillating at all. People here are obsessed with bypassing without really knowing what they're doing. You need to choose a good value, and CERAMIC caps are usually the right choice (preferably C0G) for this, not the metal films usually chosen by the modders here. Metal films sound better in audio cicuits, but power bypassing isn't an audio circuit - you need to look at the needs of the application and choose a cap type and size accordingly.
As far as the original topic here, I'm going to go out on a limb and say it's probably not worth the effort of any modding to touch the Audigy.
