1) Tune to the band you want (XM/AM/FM)
2) Tune to the station you want
3) Press Audio, and either select an EQ (EQ1/EQ2/EQ3) or just set the balance/tones as you want
4) press Band to return to Band screen
5) Press and hold the preset button on the right that you want assigned to that station and Audio settings.
If you have station presets already, and just want to change the Audio for them:
1) Press the preset button to tune the band/station you have assigned
2) Press Audio button on the left, and select an EQ setting or customize the balance/tone controls
3) Press Band button on the left to return to Band screen
4) Press and hold the preset button for this station. This memorizes not just the station, but the Audio settings too.
Mega cool feature having optimized Audio settings for each pre-select.