To answer my own query, the ritual to summon me would require:
- Frostmourne
- A Jackson Kelly guitar
- A football (or soccer ball for you weird Americans and such countries)
- Optics, by Eugene Hecht
- Kinder chocolate
For the ritual to succeed, you must first stick Frostmourne in the ground in the center of the pentagram, then rest Optics by Hecht on its blade. Then you must pick up the Kelly and play Megadeth's "Holy Wars...The Punishment Due", including the solos, while doing tricks with the football (all this while facing the book and inside the pentagram's circle). At the end of the song, hold the Kinder chocolate bars above your head, and I will appear, take the chocolate, and be your friend for all eternity.