How to change iTunes BackUp Location?

Hello,
I have 256GB SSD as primary on my MacBook Pro,
Also iPhone 5 32GB & iPad 2 64GB BackUps on it with OS X.
Thats alot of data if i want to make the BackUps & Transfer Purchases.

So i have erased the BackUps & Apps from the Library Folder,
But still i don't know how to make a Folder in my secondary HHD with
750GB the Target Location for iTunes BackUps & Transfer Purchases?
PLEASE help