If your adams apple is in the way, swallow to keep it as close to the throat as possible. Now (while still holding the swallow) grip your throat tightly as the above guide says. You will experience a nice, warm feeling in your head as your vision dims. This might take a few seconds to happen. After about a week of trying and getting nowhere, I finally managed to start passing out! The guide is correct that your hand should be placed around the middel of the neck / adams apple.