Changing the ATF?

Does anyone have a how-to on changing and correctly flushing the Automatic transmission fluid?

I've been quoted £140 for this work, so would like tomake a saving by doing it myself - ESPECIALLY as it needs to be done quite regularly with the correct Fluid (Amsoil !)

Thanks

i don't know if there's one in the tutorial section. but try to search. but it's qiute simple..