The Vipati mantra became the Gāruḍa mantra par excellence by the tenth century. I discuss its early and elaborate ritual system at length in my impending dissertation, and here I collect the web references to it that I cite. Each is given some amount of explanation there, but here I simply list:
- Hindu.com (2)
- IndiaDivine.org (2)
- IndiaDivine.org (3)
- Bluegaruda.com (now khyung.com)
There are even more links and references, but these are representative.