Lauren -
loaners come from your audiologist or your doc's office.
Cochlear promises a turnaround time of 5 business days - and both times I had to send my BP100 in for repairs, they made good on this promise.
I contacted Cochlear directly about my issues, using their online support, but you can also go through your audiologist.
If you contact them directly, they will want the serial number of your BP100 to make sure it's still under warranty. Then they will give you a return item reference number and their account number @ Fed Ex so you can send your BP100 to them on their dime.
Make sure you insure the package (again on their dime) in case for some reason your BP100 gets lost on it's way to Cochlear. Although this isn't a common occurrence, you don't want to be out approximately $4,500.
If your BP100 was programmed by your audiologist, Cochlear will return it to him/her for programming and you'll have to pick it up there. If it wasn't programmed - turns out mine wasn't - they'll Fed Ex it back directly to your home address.
The new battery insert is a bit of a pain in the *ss - you have to lift it up to insert the battery, but you'll get used to it.
The new (easier) buttons are like a dream come true.
Good luck,
Jan