I have never worked on this particular vehicles steering before, But have experience with other (older) vehicle's. Generally the shaft is held in place into the coupling yoke by nothing more than a small allen head set screw or some type of set bolt. (assuming that the cherokee's have the steering shafts that are flat on two sides and rounded on the other two) Perpendicular to the set screw/bolt there will be one or two small tack welds just as a little insurance from the factory. I am not sure if the newer vehicles are like this, But I have pulled more than a fair share of columns from pre 80's cars and trucks!
exactly what happened to the shaft? did the entire shaft snap? If you are looking for some up-grades,
I have a Ididit Tilt column/shaft in my hot rod andd this was a great kit! I have also installed a Flaming River column (no shaft) into a 71 camaro, this was also a great piece! both were unfinish (cheaper) and were real easy to paint. another option is find a late 70's early 80 chevy van, the tilt column and shaft should bolt right into most jeep vehicles, Nut be sure to maesure just in case cause again, I have personally never worked on the steering of this vehicle.