2006 Honda TRX680 Rincon Factory Service Manual, Page 116Get this manual
LUBRICATION SYSTEM Check the oil cooler hose joints and seams for leaksCheck the oil cooler air passage for clogging or damageStraighten bent fins using small flat blade screwdriver and remove insects, mud or other obstructions with compressed air or low pressure waterRemove the bolts and oil pipes from the oil coolerRemove the O-rings from the oil pipesOIL COOLER
Remove the four mounting screws and oil cooler from the radiator