Today I changed the water pump on my '58 (2009) Avensis, after noticing the noise. I ordered a Meyle pump online from a seller who sold other brands. The kit also had the gasket and three longer bolts due to the thicker mounting points. Beware of kits that may not have the longer bolts!
After draining the coolant I removed the belt and started undoing the bolts to the water pump. I had only removed the engine and battery cover, but no other panel. I could have removed the panel by the wheel arch, to get to the lower bolt to the panel. That bolt was fiddly to remove and replace.
The pumps look different as the photos show, but fit perfectly. The difference in thickness of the bolts, plus longer bolts to compensate.
I fitted a new belt and noticed it was shorter on the adjustment. 12 mm was used on all bolts except the for the lower alternator support bolt, which is 14 mm.
I used genuine Toyota long life coolant mixed with de-ionised water. I didn't want to use tap water, and it's cheaper than pre-mixed coolant. Will check coolant level tomorrow.
The old pump bearing is rough and noisy, when spun by hand. Caught in good time.