which model is yours ?
as gear oil is not a routine matter, so betther get it changed from toyota.
i got my passo's 2007 ATF changed from toyota I-9 islamabad,
i think for about 7500 Rs. (3000 oil, and 3500 labour)
if you have budget, get it done from toyota, otherwise some local good mechanic, who will not ruin the car;s gearbox.
passo 2004 to 2009 have ATF oil,
passo 2010 onwards have CVT oil