How do you move a CALayer instantly (without animation)

You can also use the convenience function

[CATransaction setDisableActions:YES] 

as well.

Note: Be sure to read the comments by Yogev Shelly to understand any gotchas that could occur.

As others have suggested, you can use CATransaction.
The problem comes arises because CALayer has a default implicit animation duration of 0.25 seconds.

Thus, an easier (in my opinion) alternative to setDisableActions is to use setAnimationDuration with a value of 0.0.

[CATransaction begin];
[CATransaction setAnimationDuration:0.0];
layer.position = CGPointMake(x, y);
[CATransaction commit];