Going single servo isn't hard with these trucks. But with the weight of these trucks and the big tires you can't go single servo and have a servo saver. There's no servo saver stiff enough. So you simply ditch the saver, pop on an aluminum servo horn and make a short link out of rod ends. I think a Jato steering link is the right size if you don't want to make the link.
There are 2 things you need to do this right. First is you want the link to be just the right length to get the servo horn and the steering bellcrank as parallel to each other as possible. Second is you obviously need a strong, high quality servo do deal with the fact there's no servo saver. I run a Hitec robot servo that's very closely related to the regular digital Hotec's with 333pz and it's taken some good hits over the years and still going strong. Some have even broken the aluminum servo horn and the servo emerged fine. Obviously won't be the case with lesser servos though.