@dealvr
I believe changes are free online, $40 over the phone.
Mocha is correct about cancellations though, AFAIK.
@eve
If you have BA miles, you need to use BA to book. There will be hefty fees to TLV. Sorry.
Dan was referring to using your BA miles to book western hemisphere travel flying AA.
For example, if you want to fly NYC-MIA, use your BA miles to book a flight on AA planes, but you need to book with BA regardless of if you end up flying BA or AA, because its BA miles. (There's no way to fly BA to MIA, I'm just giving an example)