there is a release tab on the cable adjuster that has to be pried up with a pocket screw driver and then the clip can be pulled up ,, once you have the cable ware you want it , slide the clip down to lock it back into place...
the shifter will not lock into park ,, if the cable is out of adjustment it may not be going all the way into park , or not letting the shifter go all the way into park ..... a sign that the shift cable is out of adjustment is , does the shifter go into every gear , park , rev, nutrial , drive , 2nd, low ,, if it does not then its out of adjustment
if it does then --
well, make sure the brake lamps are not on all the time,,
or the shift lock out actuator and its bracket may be loose, both located on top of the steering column , on the top of the shift tube ,,,,also sometimes,, very rare , but there is a small lever in the shift tube that locks the shifter in park , have seen the pin that holds it in place come loose or fall out , or the lever itself is broken ,,,, this makes more sense to me ,,, you would have to lower the steering column to look at the condition of this part see pics below
its located about a inch from ware those loose gold bolts ware on the shift tube