Peavey Guitar Amp Channels

I have a late 70`s Peavey Mace VT guitar amp, it has 2 channels and both can be combined in paralell. How can I rewire the amp to combine the channels in series. I have a schematic for the amp if anyone needs it.

What do you mean "series". What are you trying to accomplish with this connection?

Do you mean the speaker outputs? - if so you need to tell us what impedance speakers you are trying to use.