Yes like the others have said - I'd never done it myself until recently & it's brill!
The containers will expand slightly - making the plastic go out of shape a little and the contents go yellowy in colour but once it's defrosted the bottle goes back to shape and the milk looks white again.
I freeze milk too. To defrost, bigsister, just leave it in the fridge overnight. If you need it in a hurry, you could always defrost it in the microwave, but I wouldn't recommend that unless it's an emergency, as you might inadvertently heat it up. BTW, leelapops, if you give it a good shake once it's defrosted it's not watery.
My Granny only drinks whole milk and freezes an emergency pint, which I know I have had in my coffee. I can't stand whole milk but would never tell her that - just because I love her.
Whether it's been frozen or not, I just get on with the not so nice task for my taste buds LOL