How are pulleys used to change the chuck speed of a pillar drilling machine?

The pulley attached to the motor usually has a large wheel on bottom, two medium wheels in centre of the stack and a small one on top. The front, or spindle pulley, is fitted with the large wheel on top. The drive belt can go from top at back, to top at front -thus driving the spindle slowly. If you changed the belt to the big motor pulley and a small spindle pulley the spindle would rotate faster.