More information would be helpful. Engine size, and if it looks like it's leaking from one pulley or several? My first thought is that the front seal is leaking around the crankshaft pulley. Other oil leak sources are the timing cover, the valve cover(s), or even a cracked cylinder head, could let oil trickle down and get slung around by the pulleys. What's the highest point of the engine that looks like oil is leaking around? Either way, it should be repaired.
You can make a survey to the people around your community asking them if they are an minivan owner.
Put an 18mm wrench on the lower tensioner belt and rotate CCW to loosen the tension. Remove the belt from around the alternator pulley, and slowly release the tensioner. Unwrap the belt from all the pulleys and install the new belt following the belt diagram located near the radiator support. ALWAYS make sure the grooved side of the belt is contacting the grooved pulleys, and the smooth side of the belt is contacting the smooth pulleys (Idler pulleys). Groove to Groove -- Smooth to Smooth
Should be self-adjusting unless tensioner is bad get a tensionier bar from the auto store. Place it the hole or around the nut moves the tensioner, either up or down.
The way it fits around and on top of the pulleys.
The Pulley has a wheel and spins at the top
The Sun doesn't revolve around Mercury, Mercury revolves around the Sun. For Mercury to revolve around the Sun, it takes 88 Earth days.
Mercury is a planet. By definition, it revolves around the sun.
Complete , all the way around, about $600 in parts.
no mercury does not have rings
The way the alternator belt raps around pulleys in the automobile differs by vehicle and engine. An alternator belt in an older vehicle usually just went around the fan blade, the water pump, and the alternator. Today's vehicles are more complicated and might require more pulleys.
Usually you'll have some leaking around the plug... get a flexible necked mirror and a flashlight and look around it for leaking cooolant.
Mercury has no moons.