The schematic, overlay and PCB I posted is very simple, 5 resistors, two variable (trimming) resistors, 1 capacitor, 3 diodes and a very cheap and common IC. (Plus the two push button switches or similar to make it go to one of the two positions of course).
I'm not sure how you hoped to accomplish your goal if that is really too much for you, because it cannot get any simpler. In other words... What kind of advice do you need to reach your goal?
I'm sure you could build this... Just dare (it's quite cheap anyway).