Kamakhya is deeply connected to the Dasa Mahavidyas (the Ten Cosmic Wisdom Goddesses), particularly Kali, Tara, and Tripura Sundari. The text guides the practitioner on how to invoke these energies.
The Kamakhya Temple trust ( Bordeuri Samaj ) or Bengali Shakta mathas (like the one at Tarapith) often provide specific paddhatis (ritual guides) to sincere students. A PDF cannot replace the Shaktipat (grace) of a teacher.
If you absolutely need a digital copy for personal study (not ritual), search for on academic databases rather than random download sites.