Goodrick chose this word carefully. "Advanced" implies a destination—a place you arrive at where you know everything. "Advancing" implies a process. You never finish this book. You return to it every five years, and you find new wisdom in the same paragraphs.
Most guitar books teach you what to play (scales, chords, arpeggios). Goodrick teaches you how to think about playing. Here are the core pillars of the book that every searcher of the PDF needs to understand.
If you are determined to have a digital copy, here are the current (as of this writing) legitimate sources:
Most guitarists look at one string and panic. Goodrick devotes significant real estate to playing melodies on a single string to force intervallic understanding. He argues that the reason guitarists get lost is that we have six redundant strings covering the same notes. Remove five strings, and you finally understand the fretboard logic.