Subaru engines have a radiator and water channel design that uses pumped and pressurized coolant to stabilize its internal temperature. Unlike most internal combustion engines, instead of a block and head, there are water jackets mounted around a main crankcase which cycle coolant through the engine. The primary water pump is mounted in a tight space on the front of the motor, and the average backyard mechanic can replace this pump in about two hours.
Drain the coolant from the system by disconnecting the lower radiator hose and allowing the fluid to collect in the drain pan. The hose has standard “pinch” hose clamps, and can be disengaged by gripping the clamp’s arms together.
Remove the radiator by disconnecting the upper hose, fan shroud and fan, and the top bolts holding it in place. Once free, it will slide out towards the top of the motor.