How to convert active bass to "stereo" (like Rick-O-Sound)

I've got two basses, both of which are active and I believe they both have passive pickups: Schecter Stiletto Extreme 4 and Dean Edge 2 (five-string). I'd like to convert one of them to have each pickup outputted separately. I've tried to read about this and it seems that this is easier in a passive bass. So, I'm assuming step one would be converting the bass to passive.

What do I need to do to accomplish this? I'd prefer to do the work myself, and I do have some soldering ability. Ideally I'd like to do it in a way that is undoable further down the road. So, a single stereo output (TRS 1/4" most likely) is necessary. If replacing the pickups is necessary that's fine.

Requiring a stereo cable is not an issue for me...I only play at home so there's no concern about a cable crapping out or being lost at a gig.

Obviously the controls on the bass will have to function differently if there's no active preamp in the bass. If I could have a master volume, and separate volumes for each pickup, that would likely be sufficient. Any other functionality would be gravy.

So, how can I convert a bass to have stereo output like Rick-O-Sound?

 

What about the wiring of master volume and each pickup's volume?

 

How about instead of master volume there's a mono/stereo switch. When switched to stereo there's the volume for each individual pickup and that's it. When switched to mono, though, there's a blend knob for the two pickups. How feasible is that?

 

Got any tips for how it's done, or where I could find how?

 

Would this wiring scheme be correct for each pickup having its own volume, and a switch that chooses between mono and stereo (with mono being simply the two pickups in parallel)?

 

I'd like to make it passive. For one it seems more straightforward that way, and also I'm not a huge fan of the sound of the existing preamp.

 

I don't want any tone controls...I'd rather do that elsewhere. Does the sketch I posted above look like it will work?