How do I switch to and from 4wd in my '95 Ford Ranger?

I know very little about cars/trucks. With my truck you have to turn the little knobs on the front wheels then turn a dial on the panel inside. It doesn't matter which way I turn them on the wheel, the lights inside indicate it's ALWAYS in 4wd. I don't know which way to turn the knobs on wheels (clockwise or counter clockwise) to be in/out of 4wd. Help. Thanks