Swap Extruder pin configuration

[Ronny91 0]

Hello,
first, my problem is similar to these posts but they didn't quite help me solving my problem:

 

 

I tried to upgrade my Ultimaker Original with TMC2100 stepper drivers and somehow made an error and my board blew up. I already replaced the broken Power supply and the IC1 on the board and was happy that it starts up again but then I noticed that the extruder wasn't working. I swapped cables and drivers but it's neither a problem of the stepper motor nor the TMC so my guess would be that the mainboard is fried somewhere at extruder E0.
Since the UMO has another free spot for a second extruder I figured it should be possible to switch pins with E1. But there it gets very unclear for me what to do and how. I found a Ultimaker Original Marlin ZIP file and looked into the pins.h trying to swap E0 and E1 pins but I have no idea where to do the changes.
Should I just swap it everywhere?

 

Any help would be greatly appreciated.