You might want to check the cable first.My wife has a 1992 and the cable was just caught.And did not need repair.
You don't , you replace the linkage cable from shifter to transmission
It is the part that the accelerator cable hooks to.
Loosen the shifter cable not on each end of the shifter cable. The shifter cable will come off. Reverse the process to install the new shifter cable.
If the cable is broken you should replace it.
Buy a new cable
To change the shifter cable on a 1998 Oldsmobile Silhouette, first you need to disconnect the cable from the shifter, then disconnect it from the engine's control arm. Then replace it with the new cable and make sure it is functioning.
The 1997 Chevrolet Lumina shifter cable is held in place with a swivel nut on each end of the cable. Loosen the swivel nuts and the cable will come off.
To replace a mountain bike shifter cable, follow these steps: Shift to the smallest gear on the rear derailleur. Loosen the cable anchor bolt and remove the old cable. Thread the new cable through the shifter and housing. Pull the cable tight and secure it with the anchor bolt. Test the shifting to ensure it is working properly.
To replace a bicycle shifter cable, first shift to the smallest gear. Then, loosen the cable clamp bolt and remove the old cable. Thread the new cable through the shifter and housing, and secure it with the clamp bolt. Trim any excess cable and adjust the tension as needed. Finally, test the shifting to ensure it is working properly.
The shifter cable connects the shifter to the transmission.
I've bee told that the 1991 model doesn't have a cable it works off the speed sensor.
Shift cable adjustment, low fluid, internal transmission failure.