I've put on three or four Vetters. The process varies with the model of both the bike and the Windjammer series, and if the 'Jammer has the turn signals in the fairing.
Mounting instructions here:
http://www.craigvetter.com/pages/vetter_fairings/Vetter-Fairings-main.htmlNice and pretty straight forward if you have the installation kit. These frame mounted fairings are far better for stability particularly in cross winds than the bar mounted types
Most require front turn signal relocation. Some allow the headlight bucket to remain. The Vetter install kit includes a Vinyl bag to house the wires that are in the bucket. Some bikes allow the upper fork covers to remain. Some require those covers to be removed. It always torques me when lazy hackers literally use a hack saw on the original parts, like turn signal stems. It's burning your bridges so you can never go back. Stupid, imo.
Horns are usually displaced. The Vetter frame bracket has a place for it. I set up the 'Jammers so with four bolts and a single plug disconnect, the fairing removes for engine maintenance. Lowers add to that process some, but they are worth it in the cold climes.
I use set back blocks on the stock bar mounts to move the bars closer to the rider. This makes it easy to sit up on the bike, keeps the mirrors from mashing into the shield during parking lot maneuvers, and the fairing keeps the air from trying to blow you off the bike at speed. In fact, you actually get wind on your back pushing forward a little. This is probably why the wind drag on the whole bike with fairing is better.
You don't need to change front fork springs, unless you pack gold bars in the fairing pockets, or they have really sagged from age.
I put a Windjammer IV on a 74 CB550 back in the 80's. Still have it. Same fork springs. Never noticed any problems.
I just weighed one of my Vetters at 18-19 lbs. The bracket is a couple pounds more to add to that. I suppose that is of some concern if the rider is overweight. 'nuff said.