Spark plug DIY is a operate subject. Please use that thread for more discussion on this. With patience and appropriate adapters the plugs can be removed and installed without taking other things out.

just a nit ... typo -- exhaust manifold --> intake plenum or better still cowl/wiper_motor.

 

This forum played an indispensable role in achieving this, and I'm truly grateful! Here's a breakdown of the steps I followed:

• Initially, I introduced 22 oz. of Prestone Total Cooling System Cleaner to the coolant.
• Over the course of a week, covering around 200 miles, I operated the vehicle.
• Next, I proceeded to open the radiator drain and extracted approximately 1.5 gallons of coolant.
• Following this, I supplemented the system with 22 oz. of Prestone Total Cooling System Cleaner and approximately 1 gallon of distilled water.
• I continued driving the vehicle for one more day, covering approximately 35 miles.
• Afterward, I tackled the task of opening the radiator drain and the drain beneath the engine block, which required some effort to access.
• I successfully drained approximately 2.5 gallons of coolant.
• To replenish the system, I introduced 1 gallon of Genuine Toyota Fluid 00272-1LLAC-01 Long Life Coolant and 1.5 gallons of distilled water, resulting in a coolant-to-water ratio of about 35% to 65%, should be fine for Texas winters.
• I ensured the overflow tank was filled to the designated full mark.
• Lastly, my to-do list includes regularly monitoring the coolant level over the next few days and adding distilled water if it decreases.

On a side note, I managed to remove and thoroughly clean the overflow tank by gently pulling it up.