Have a manga distributing company buy the rights, translate it into English, put it to paperback, and send shipments of it to stores that sell manga?
I'm not really sure what the question is here. The live action stuff, I can understand. But why do we need to do anything different for the manga? Fans of manga and Kamen Rider will find out about it, but the average anime/manga fan probably won't even know about it until they decide to go manga shopping one faithful day. Manga doesn't get nearly the same advertising as anime, and as far as I can tell, it is famous for getting a proper, faithful translation way more times than anime. Even if the anime is picked up by 4Kids, chances are the manga was treated with better care and respect.