As you like to say, RTFA. They are both surgical procedures and the procedures are _identical_: make a hole or cut in the scrotum, pull out the vas deferens. In a vasectomy, you now cut the vas deferens. In a RISUG, you now inject the fluid into the vas deferens. Push the vas deferens back into the scrotum, repeat on the other testicle, and cover the wound. Both procedures can be done through a very small opening that requires no stitches, in a doctor's office, in under half an hour.