Rav4 2002 antifreeze change

Hello everyone again, I just bought a 2002 Secondamano Rav4.
I have always liked to have the perfect mechanics cars and with this I want to do the same ...
my question is that, having already changed the antifreeze in Otrs vehicles ... I had never given me the case of having an expansion boat in the low zone of the radiator and a cap in the now commented radiator.
As I have read, the radiator has an emptying cap, a positive thing that in three vehicles that I have do not bring ... and for what will be easier for me to drain the liquid.
I first ask you if it is better in cold or hot ... on the subject if it is more liquid when it is hot.
The second is where I begin to throw ... if for the radiator plug or in the tapon of the expansion vessel that I have in the low zone ... I do not know if it will have any communication with the engine or only have in sleeve towards the radiator.
Greetings ... If someone has a Brico of the East model of Rav4 of 2002 Gasolina 1.8 I get it.
All the best

In cold it is better and safer, start with the radiator and check the bleeding points to purge the air, after this without the cover, he hopes that the elctro will be shaped three times and then cover let cool and fill the radiator again, and finally fill the expansion deposit.

We are going that the expansion vessel has no more communication than the sleeve that comes above the radiator. I think it is so. No?

Thank you very much for your information, I find it very valuable.
Saaits

This is the only communication because it is for when the water is heated as it occupies more volume has where to go and does not burst by the lid.

Then I do not explain, if it is the only communication from the top coming from the radiator, so that it has a level of Max and Min ... if it was empty, would not do the same function of receiving the liquid from the radiator cap in case of warm?

Excuse me for being so heavy, but it is to know a little more about the subject ....
S2