how doi mend knobson Electrice belling kensington cooker?

I stupidly took a knob of to clean.couldnt get it back on as there is a spring which you have to somehow level up to get it on right so the regulo is synchronised. The knob of the small oven is on but not level with the others so there is no way of knowing what regulo the oven is on. My husband to a knob off one of the hobs to see how they work and we now have the same problem with that. There seems to be a screw head which can be seen just inside. Do we do anything with these.?