It takes some serious balls to learn this style because you're going to have accept the fact that when you're starting out with it you're going to get hit more than you do now. Even a guy like James Toney got roughed up when he was developing it. I guess it is a process as it can be developed.

It's more than fighting out of that particular stance, it has to feel natural to you, and you need to understand what comes with this stance. You can't be a 1-track minded fighter when using this style. Watch some of the older fighters like Archie Moore, Jersey Joe Walcott. They throw a rising jab that often from the hip. This jab has to be fast and crisp This is big part of this type of defense and has to be developed before this stance becomes your mainstay.

With your left hand low you become more alert of your opponent's right hand. How are you going to deal with it? Are you going to slip it, block/deflect it with your shoulder, etc... With defense you have to look at yourself and see what's open or has the potential of becoming open. Here's a quote by Thomas Tabin that'll explain what I'm talking about:

"What you first need to know is that every guard has openings. Every single one. it is up to you to find those openings. you want to first get a good understanding of the target areas of the body and the angles that lead to them. for every opening there is an invisible plane that your fist travels along like a pipeline which leads to the opening. in order to land you must put yourself in sync with the angle which leads into the opening you see. It’s very important to use dynamic punches. You will have to adjust your punches slightly shortening them or lengthening them so that you are in sync with the appropriate angle or pipeline into the body. you will also have to adjust where you are in relation to your opponent with footwork i.e. you may have to move more so to your left in order to land a left hook or moreso to your right to land a right uppercut. So its important that you be able to adapt to the changes your opponent will present with his movements around the ring and with his body in general. you want to punch with the idea to get past his guard. Don’t punch just to punch. I see alot of kids just punching for the sake of punching and they will never get past a guard doing this."

While you're practicing with this stance that's the kind of stuff that you have to consider. What angles are you more vulnerable? How are you going to protect those angles. On the other hand use this wave of thinking on your opponent. Weigh the advantages and disadvantages of their style. When Schmelling fought Joe Louis he fought on the outside of Joe's jab and had a big bag of tricks to draw upon for that situation. Yeah it's complicated but this has to worked into your training so that you can use this insight while you're fighting. I think it work wonders if you had a very alert sparring partner that is very familiar with the ins-and-outs of this particular style, because then it's more like a chess game as you'll be fighting for an opening and trying to protect your own angles. There's a lot that goes into it, and frankly there's not enough time to put it all in one post. Maybe I'll come up with a post with deals with ring generalship which will cover angles, footwork, fighting off the ropes, etc...

Knowing some of the advantages/disadvantages of this stance you should be very adept with a regular conventional stance as well. Just like when Mayweather had to assume a more conventional stance to better amount an offense in the later part in his fight with Zab Judah.

One last thing I'll go over in this post is what spaceballwon brought up. Radar. You'll need to become very aware of what's coming if you're going to use this stance. One way is to shadowbox with an opponent which can help you practice feinting and moving while trying to get them to open up an angle. Another thing is from one of Andre's posts from 'Different/Alternative Training Ideas':

Quote Originally Posted by Andre
This takes a bit of patience and practice ,

With sparring partner or friend practice just relaxing your arms (not necesarily out and in a fixed on guard mode either ) just whatevers comfortable and freed up ; so you can concentrate on other things flowing together.

Now just practice letting his blows come through but you simply lean back out of contact and then as you straighten up follow his glove back with your own attack. Follow the elbow back and go low OR follow the glove back and go over it ,wherever the opening occurs.

This allows you to set your visual skills into the correct timing mode.

It also sets you into a rythem whereby your attacks will be harder to see comming for him due to his own retreating movment ,therefore more devestating once you put it into practice in real ring terms.

HE has to work in with you, you both just remain in a fixed stance to begin with and add stuff and get faster as you go along so your reactions catch up to your vision and visa versa.

After a few months of practice you can bring other footwork into play ,but for a start begin at the start.

Swap around so you both a get the appreciation of the exersize.
Also for another fight to watch, check out round 12 in James Toney's fight with Jirov. Take a look on what he does when he has his back on the ropes.