i've done one the other week but its already shipped to the customer. I'll ask if he already fitted them and if he could snap a couple pics if not.
The speedo can only be mounted on the right side of the bike, due to the direction it needs to rotate. If you decide to swap the disk to the other side, the disk and the speedo gear will clash. You can however keep the caliper on the left leg and behind it.
A dual disk conversion is fairly easy, the only thing that needs modding is the speedo pickup. Not necessary tho to ride safe. Like PJ already said, go over to 'the dark side' for some detailed how-toooooooooooooos
remember you will need an extra disk, longer bolts, extra caliper, new brake lines, brake fluid, copper washers and a day off. Furthermore, i strongly advice getting a new brake master cilinder from a cbr or gsxr or other sportsbike with 2 calipers. The extra caliper requires extra fluid to be moved around and the stock master is not up for that. It's only up for the bin anyway..
If you want to do it in one day, get an extra speedo drive gear, get it turned down to fit in the disk, weld 2 little knobs on them and mill 2 little flat areas in the rear of the second disk to accomodate the knobs on speedo pickup. Thats how i do it normally. Its the cleanest and easiest in my opinion. Like i said, will try to contact the customer for a pic or 2.