Rooting devices is EXTREMELY easy. It might seem hard, but really it can be done with the click of a button. I will tell you how to do it on here, but you can also find my tutorial here
Step 1: Downloading NRT
*Just letting you know, rooting VOIDS your warranty!*
There are two root programs that I’ve used. Those would be the Nexus Root Toolkit, and Nexus 7 Toolkit. I find both easy, but NRT is easier, and I will be using NRT for this tutorial.
Step 1. Download, and run the program. Click OK and stuff until you get to the menu shown in the picture.
As you can see, you have the driver installation guide, backup/restore, root, OEM lock, unlock, and flash stock unroot. Those are pretty self explanatory, so I won't explain what they all are.
Step 2: Root your device!
Step 2. Unlock your device. Plug your Nexus into your computer via USB. It will tell you to allow USB debugging on your nexus. To do this, go to developers options (If you aren’t a developer, go to About Tablet and hit the build number about 8 times.), and check USB Debugging. It will ask you to trust your computer. Now, click the Unlock button. Allow that to do its job, and once it redirects you to the menu again, click Root. It will do the rest. Once you get back to the menu, your device should be rooted. Go on your Nexus and run the SuperSU app, and then BusyBox. To test to make sure your device is rooted, you can get Root Checker. On Root Checker, press Check. If status shows Rooted, your device is rooted!
Once its rooted, your warranty is voided. I’ve had my Nexus replaced before, and I rooted the first device, but I flashed Stock android on it and locked it again, and they replaced it. So, apparently, your warranty is only void while your device is rooted.