All the files you need in one zip (adb+SuperSU+fastboot+Windows drivers):
Step 1. Put your Nexus 10 into Bootloader mode by turning off your Nexus 10. Then hold down Volume Up, Volume Down, and Power buttons together.
Step 2. Once in bootloader menus, connect a micro USB cable from your Nexus 10 to your computer. Update the drivers on your computer.
Step 3. Let’s unlock the bootloader. This WILL ERASE EVERYTHING on your Nexus 10, make a BACKUP before you DO THIS!!!
Open a command prompt or terminal and type:
fastboot oem unlock
For Mac, type:
./fastboot-mac oem unlock
For Linux, type:
./fastboot-linux oem unlock
Step 4. Go to your tablet and unlock your Nexus 10.
Step 5. Next let’s flash CWM recovery, so type:
fastboot flash recovery recovery-clockwork-touch-126.96.36.199-manta.img
./fastboot-mac flash recovery recovery-clockwork-touch-188.8.131.52-manta.img
./fastboot-linux flash recovery recovery-clockwork-touch-184.108.40.206-manta.img
Step 6. Type the following but DO NOT PRESS ENTER yet!
adb sideload CWM-SuperSU-v0.98.zip
./adb-mac sideload CWM-SuperSU-v0.98.zip
./adb-linux sideload CWM-SuperSU-v0.98.zip
Step 7. Choose “Recovery” using Volume buttons and your Nexus 10 should boot into CWM Recovery.
Step 7b. (ONLY FOR WINDOWS, Mac and Linux skip this step) Now, open up Device Manager on your computer (if using Windows, otherwise skip this step) and make sure you see some kind of “ADB Interface” driver. If you don’t, quickly update the manta with exclamation mark with the same drivers you used earlier. Reboot into bootloader then choose “Recovery” and enter CWM Recovery again.
Step 8. Choose “install zip from sideload” and hit ENTER in your command prompt/terminal for the command you typed earlier in Step 6.
Step 9. If it was successful, you should see Superuser app and root being installed. If not, try again from Step 7 and make sure your drivers are installed if using Windows.
Step 10. That’s it for now, you should be able to root your Nexus 10.
Thanks to shimp208 for the sideload method, ChainFire for awesome SuperSU and to all the developers who are worked on CWM recovery! Now waiting for a stable version of CWM…