I have a YouTube channel where I publish videos on repairs and projects I do around the house. I have a very detailed video on replacing the water pump, drive belt, and thermostat on my 2013 Lexus GX460. Check out the link below. I also made a thorough write-up on the procedure, which is also linked below.
http://vancewillis.net/files/2009-2020_gx460_water_pump.pdf
I posted this in the how-to section, but thought I would share here also.
Enjoy!