You can start to read about it here at post 26: http://www.speedzilla.com/forums/rc5...vorit-mod.html
There is also more information here:
Yes, it's an aftermarket fan that replaces the stock one. Spal has been around for a while now, all their fans are made in Italy, and they are quite the bargain at $35 on eBay. I don't even want to think about what Honda will charge you for the garbage stock fans.
Basically you'll have to pull the radiators, make some brackets and take the wires and plug off the old fans (unless you want to source new connectors and put those on the new fan). Install them and fill the rads back up and away you go. I only run one fan right now (pulled off the right stock fan) and it works pretty damn well. I will be installing the other side soon, but just to make the bike cool down even faster. Trust me, at a dead stop the one fan will drop temps much faster than stock, but two will make it even faster.
You want to get the fan (or fans) off eBay. Search for "spal 5.5" the seller is proair llc or something like that. His info is in those threads. You want the one with the grate, without it you will grind rocks into your radiators. One speedzilla member found out the hard way about that. Fwiw, my stock fan did it already to my right rad. The trade off is that the other one without the grate has the correct connectors on it. That's why people buy that one.
For the manual switch, all you have to do is locate the fan relay in the tail, and splice a wire into where it takes a ground signal to cycle the relay, run that wire up to a switch in the cockpit area. Run a wire from the other side of the switch to a good ground and you are good to go. Due to the many different types of switches, I won't go into that too much unless you need help. You only need a single pole single throw switch. You can google or Wikipedia SPST, or DPDT etc. for more info.