Nothing can truly replace leveling presets live, with the band, using your ears. But if you need to get things close, and you can't open it up to full volume to test levels using a Db meter, this approach works pretty well.
You'll need a pink noise generator and a loudness meter application. I'm on OS X and I use Noisy for pink noise generation and Orban Loudness Meter for measuring. Both will work using the Axe-Fx II's USB in and out on OS X 10.9.x. They also both happen to be free which is nice.