Yeah, it’s called Liber Samekh by Alistair Crowley. Traditionally the operation known as The Knowledge and Conversation of the Holy Guardian Angel takes a year to complete, but various modern authors have gotten it down to to six months. It is also known as the Abremelin Operation. A modern version is available in the book 21st Century Mage by Jason Newcomb.
It is a very involved operation requiring morning and evening prayers, and meditation, days of silence and purification, and a retreat from the world. It is not a simple ritual.
EA describes his experience with the Abremelin Operation in his book ipsissimus.