Most of the ribbon cables in similar electronic devices I encountered, could be disconnected by simply pulling them out. While 'simply' is relative...
I really would not advice to put more liquid into your keyboard, or keyboard into more liquid. Does the board still work / do all keys register? (you can check with AquaKeyTest for example)
What part of the board was hit by the soda? Did it get down to the PCB?
BTW the PCB is the (often green) plate, with electronic components, which you can see when turning the part with the switches around. The black plate, where the switches are put in, is usually described as mounting plate. In the worst case spilling liquid on any part will cause it rust and cause malfunctions. This shouldn't be the case with any dedicated washing alcohol, but I'm not 100% sure.