Is there any easy way to rewire a 4x12 cab for stereo?

[Executioner213]

I have two Carvin Legacy 4x12 cabs, and they both have an input and an extension output (so theoretically, two 1/4" plugs). I have been digging that my old Peavey Ultra 4x12 has mono/stereo capability, with a slide switch selector. I'd like to be able to use my nicer, V30-loaded cabs this way if I can. Any way a brutha could do this on his own?

 

[Executioner213]

...and in case anyone is wondering "why?"...it's so I can use just 1 cab if needed. I'm using a stereo rig, and would prefer to be able to run stereo rather than just 1 side of my amp if I can.

 

[MetalJonesy]

??

 

[Executioner213]

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https://www.carvinguitars.com/products/single.php?product=CC412