Pretty simple: 1. put on the ring 2. put the PA pin through your piercing, then hold it against the underside of your penis. I usually do this...
I found one on dhgate some time ago, but there's this on Amazon:...
I got mine at 10 gauge, it must have been 17 years ago now - I've since stretched it up to a 6 gauge, but didn't really do much for this, it was...