Gravity Falls S2 Ciphers - S2E19

The End Credits contain this image

We will use themysteryofgravityfalls.com to decode the ciphers.

The first step is decoding the numbers using the "A1Z26" cipher.
The second step is passing the words from the end of the first step through the "Atbash Cipher" (flipping them).
The third step is passing the words from the end of the second step through the "Caesar Cipher" (-3).

When we do all that, we get this.