Assuming you mean the ignition lock cylinder (where the key inserts), perform the following operations to replace:
Disconnect the negative battery cable. Remove the steering wheel.
On vehicles equipped with tilt wheel, remove the tilt lever.
On vehicles equipped with tilt wheel, remove the steering column collar by pressing on the collar from the top and bottom while removing the collar.
Remove the instrument panel trim cover retaining screws. Remove the trim cover.
Remove the 2 screws from the bottom of the steering column shroud. Remove the bottom half of the shroud by pulling the shroud down and toward the rear of the vehicle.
Turn the lock cylinder with the ignition key in it to the ON position. On vehicles equipped with automatic transmission be sure that the selector lever is in the P position.
Push up on the lock cylinder retaining pin with a 1 / 8 in. (3mm) diameter wire pin or small punch. Pull the lock cylinder from the column housing. Disconnect the lock cylinder wiring plug from the horn brush wiring connector.
Prior to installation of the lock cylinder, lubricate the cylinder cavity, including the drive gear, with Lubriplate or equivalent.
To install the lock cylinder, turn the lock cylinder to the ON position, depress the retaining pin. Insert the lock cylinder housing into its housing in the flange casting. Be sure that the tab at the end of the cylinder aligns with the slot in the ignition drive gear.
Turn the key to the OFF position. This action will permit the cylinder retaining pin to extend into the cylinder casting housing hole.
Using the ignition key rotate the lock cylinder to ensure correct mechanical operation in all positions. Connect the key warning wire plug.
Install the steering column lower shroud. Install the steering wheel.
Check for proper vehicle operation in P and N . Also be sure that the start circuit cannot be actuated in D or R .