With iOS 8, you still can't make Apple Maps disappear completely, but you can now quickly reroute navigation results into a third party app.
Let's say we're asking Siri for directions.
Give me directions to the Grand Canyon.
Getting directions to Grand Canyon National Park.
By default the iPhone will open up maps and show you an overview of your route.
You'll notice that above the map, you have buttons for drive and apps.
You tap the apps button, you'll have the option to try the same route in any other map program you have installed, including Google Maps.
You'll also have some suggestions for navigation apps that can be downloaded.
Tap the word route next to the app that you'll wanna use and you'll be bounced into that app.
In the case of Google it seems to assume that you wanna take public transit but a tap on the car icon will bring up standard navigation.
So there you go that's how to get directions on your iPhone or iPad and force it to use a third party option like Google Maps.
More tips on using your iPhone visit cnet.com/how-to.
For CNet I'm Donald Bell.