Decware ZSB please help

Hello All,

   I have one of the Decware ZEN switch box that I am using in reverse. The model I have does not have the A/B switch so I can run two  different sources. I reached out to decware but no reply. I know they are very backed up with orders. So I was hoping someone here could help me. I have good soldering skills but I need for someone that can tell me what switch I need to buy and maybe a hand written schematic diagram so I know what wires to solder to which wires. So if anyone could help please let me know

Thanks
Mark