Step One
Download the latest version of SeasonPass from here.

Step Two
Double click to extract the archive you downloaded. Then double click the extract application to launch it.

Step Four
You will be asked to enable UI Scripting. Click the Enable button.

Step Five
Click the Create IPSW button from the main screen.

Step Six
Seas0nPass will now download the latest Apple TV firmware file

Step Seven
Seas0nPass will create a custom IPSW file for you.

Step Eight
Once your custom IPSW file has been created, Seas0nPass will ask you to connect the Apple TV to your computer via a micro-USB cable and use the remote to put it into DFU mode by holding MENU and PLAY/PAUSE for 7 seconds. The power cable should be unplugged during this process. Tip: Press the buttons and insert the usb cable at the exact same time.

Step Nine
Once your Apple TV has been detected in DFU mode, Seas0nPass will upload some files, automatically launch iTunes, and beginning restoring to the new firmware.

Step Ten
That's it! Your Apple TV is jailbroken!