1994 Ford Aerostar Gear shift is sloppy

how do you replace or repair the gear shift lever,it is sloppy,as it won't go to a specific place on the gear shift indicator,it moves,but you have to go pass neutral and then back to find reverse,and drive and overdrive is just a guess as what gear it is in untill you start moving down the road,my brother owned the van before me and had it checked and they told him it's not on the transmission linkage,but in the steering columnI guess what I need to know is how do you take the steering column apart to get at the problem,and will I need special tools

thanks
jeffreylynn46