DLF
Registered
As you say, drainng the oil is simple.
To completely drain the coolant, you'll need to:
1. Remove the crossover cap.
2. Drain the radiator. The drain is on the lower passenger side of the radiator.
3. Drain the block. There are two plugs on either side of the block (circled in red in the first pic).
4. Flush the system by putting a hose in the coolant crossover while leaving both the radiator and block drains open.
Then remove the 4 bolts (2nd pic, circled) holding the adapter to the block, and change the gasket.
Put everything back, fill the fluids, and cross your fingers.
To completely drain the coolant, you'll need to:
1. Remove the crossover cap.
2. Drain the radiator. The drain is on the lower passenger side of the radiator.
3. Drain the block. There are two plugs on either side of the block (circled in red in the first pic).
4. Flush the system by putting a hose in the coolant crossover while leaving both the radiator and block drains open.
Then remove the 4 bolts (2nd pic, circled) holding the adapter to the block, and change the gasket.
Put everything back, fill the fluids, and cross your fingers.