u could get an access to your BLOWER MOTOR by first opening your ENGINE HOOD and open up your BATTERY BOX.
Then next as you would with your battery change u have to remove top outer layer of plastic cover that holds the battery plastic cap. then also remove the left half of the PLASTIC cover that covers the very bottom of the WINDSHIELD than you'lll see a WHITE PLASTIC blower motor below that windshild cover.
here go look at this instruction. it has pictures.
http://liljerk.morpheus.net/350Z/firewall/
and if u look at picture 9 in that website u'll see a oblique hole right below the windshield and inside that hole u'll see a blower motor...