External hdd

Hello,
sir
i just bought seagate external hdd
of 500 gb
where as my c drive is only 80 gb
now for my apple i pod which is 160 gb
i need to put my i tunes library in external hdd
but it coming by default in c drive
so i cant not transfer all my music in i pod
how it is possible to get i tunes library in my external drive directly
pls reply
as when i am deleting it from c drive it is going permanatly
i will be gr8ful to u
sonia