This is some common element moving functionalitywithin JS Arrays, packaged in a Angular.js factory

Angular_array_movement.js

app.factory('ArrayService', function(){
	return {
		deleteElement: function(array, element) {
			var index = array.indexOf(element);

			if(index == -1){
				return false;
			}

			array.splice(index, 1);
		},
		moveElementUp: function(array, element) {
			var index = array.indexOf(element);

			// Item non-existent?
			if(index == -1){
				return false;
			}

			// If there is a previous element in sections
			if(array[index-1]){
				// Swap elements
				array.splice(index-1,2,array[index],array[index-1]);
			}else{
				// Do nothing
				return 0;
			}
		},
		moveElementDown: function(array, element) {
			var index = array.indexOf(element);

			// Item non-existent?
			if(index == -1){
				return false;
			}

			// If there is a next element in sections
			if(array[index+1]){
				// Swap elements
				array.splice(index,2,array[index+1],array[index]);
			}else{
				// Do nothing
				return 0;
			}
		}

	}
});

Usage.js

// Just use this within your controllers, don't forget to inject ArrayService into your controller!

// Locates elementWithinArray and deletes it, returns false on error.
ArrayService.deleteElement(myArray, elementWithinArray);

// Swaps elementWithinArray with element before it. Returns false on error.
ArrayService.moveElementUp(myArray, elementWithinArray);

// Swaps elementWithinArray with element after it. Returns false on error.
ArrayService.moveElementDown(myArray, elementWithinArray);