KVO and ARC how to removeObserver

How do you remove an observer from an object under ARC? Do we just add the observer and forget about removing it? If we no longer manage memory manually where do we resign from observing?

For example, on a view controller:

[self.view addObserver:self
            forKeyPath:@"self.frame"
               options:NSKeyValueObservingOptionNew 
               context:nil];

Previously, I would call removeObserver: in the view controller's dealloc method.