It's not that difficult to crossover. It's just another set of rules. And the agreement goes both ways. KKW Dan holders will be allowed to learn the ITF rules and fight in their tournies too.
I would love to get my rank recognized by the KKW, but I can't find anything about the process. No KKW schools in my area or even in my state to my knowledge.
You don't say what state that is, but I would be REALLY surprised if there were a single state in the US that didn't have multiple schools that offer KKW certification.
Louisiana. there may be some, but I can't find any schools listed on USAT or particularly in my local area.
The USAT website unfortunately doesn't list all the Kukkiwon-affiliated taekwondo schools in a given area. A more effective way to search might be to use Google Maps to get a list of taekwondo schools near to you, then one-at-at-time visit the webpage of each school. Once you're on a website, look for the USA Taewondo logo, a Kukkiwon logo, or an Olympics logo. If you don't see a logo on the website, try checking out the photo-gallery of that school; if they don't have a gallery on the website, they probably have one on their Facebook page. Again, looking at the banners within the dojang photos, you'll often see an Olympics-logo banner hanging in the dojang.
It would be nice if more websites were just more explicit about the style of taekwondo being taught, but often you have to do a little online detective work to sort it out. I've helped a number of my coworkers find Kukkiwon-style taekwondo schools in their neighborhoods, and it's not that hard to find using Google, but only if you know what you're looking for. I think a lot of smaller schools especially don't spend a lot of money on their websites, so there's a lot of information it would be USEFUL to have that nonetheless isn't there unless you know how to look for clues.
THEN...once you find the school, as I understand it (not that I'm an expert on this), as long as you're 3rd Dan and under, the process is pretty straightforward. Your new instructor at your new Kukkiwon-affiliated school -- once he or she is satisfied with your qualifications -- fills out some paperwork that makes a request to the Kukkiwon to award you an equivalent Kukkiwon rank. It's more complicated for 4th Dan and above, as I understand it.