The male urethra travels from the bladder through the prostate and length of the penis. It is relatively close to the surface all the way from the tip of the penis to between the scrotum and the anus. If a sound is inserted into the urethra and pressure is exerted, it is easy to see the skin tent up along that portion of the urethra. The major difference after that is in how the reroute is done. Many, including those who are DIY types, pierce through the urethra, creating a small hole to pee through. Others of us who have avoided the DIY mode, preferring instead to have some who knows their anatomy and what they are doing, cut and stitch. Even though it is a relatively simple procedure, the success level for those who have tried DIY, piercing a hole through and hoping it would work, is poor. Those who have gone through the surgical procedure, which can be done as an out-patient in about an hour, have had more success.
It should be noted that due to the shortened urethra, men will be far more prone to bladder infections. This is doubly true because of the new proximity to the anus (cleanliness is essential). In addition, complications from the procedure including urethral stricture are not uncommon. Finally, contrary to popular belief, having a urethral reroute does not bypass the urethral sphincter, it just shortens the urethra. If proper hygiene is used, there should not be any types of complications.