What is fastest way to do coolant control valve?

Since it causes no real problems, I would just wait until a bit of better weather comes along, even if it means next spring.

 

I agree with @TMR-JWAP that this is something you can go a long time not getting done and its best to wait when you have the time... It only effects MPG on your cold engine starts because coolant heat storage pump won't work once the sensor fails.

However, when it is time to get it done, the quickest way to do it is to buy a couple-few packs of these: 4 Piece Fluid Line Clamp Set

And also buy one of these: 2FT Flexible Wire Long Reach Hose Clamp Pliers For Fuel Oil Water Hose Auto Tool | eBay

Then simply remove the inverter mounting bracket that gets in the way and clamp all 3 hoses, then remove the hose clamps and replace.

I haven't had issues with too much air getting in the system in a way that causes a problem... But I do have to top off the coolant level a couple times via the radiator cap when engine is cold.

Also a warning... The first time I did this I followed instructions from a guy on YouTube who used mini vice grips with hoses on the teeth for clamps and they leaked and I had to work super fast with three hoses, or maybe less than that leaking.

I was cursing and cursing and scrambling to not make a mess and apologized to my neighbors with a little kid afterward because I was swearing louder and more than I have in the past 10 years because I don't like making messes!

 

This, definitely. There isn't space to get pliers into the right position for some of those clamps.

I used corks instead of hose clamps, but in any case, something to close off the hoses.

There is a very long thread on how to change that valve. While you are waiting for a warm day, go ahead and read through it.

When we did mine my son and I had a devil of a time trying to get the valve back in through the top, and in the end resorted to loading it in from under the car. Even with the inverter loosened and propped up with a block of wood. Would it have killed Toyota to have left a little more room for this sort of thing? Taking the radiator out is also a big PITA because of the lack of a few more millimeters of clearance.

 

Most people remove the headlight to make it easier... Of course if you've been sticking your hands into tight spaces in cars for decades and develop the hand skills it's not so bad compared to other challenges.

 

I am really thin and would wager I can get my hands into areas in a car most of you couldn't. The problem with the three way valve is that putting it in isn't just a case of "slide this piece into a narrow slot", it is more of "do a complex series of rotations and translations to dance this part around all the obstacles between the outside world and its final destination". Kind of a 3D Tetris like task. In the end we found it easier to put the new one in from below.

 

Some solve problems similar to 3D Tetris faster than others... And yes the first time I did one of these I jacked the car up to increase my options, which was helpful due to my hose clamps not working correctly.