To change the rear compartment lid lock cylinder, get rid of the rear compartment lid lock cable assembly latch and the rear compartment lads appli. Next, remove two rivets. For cases of Oldsmobile models, pull out the rear compartment lid lock cylinder and shim; in cases of Chevrolet models, pull out the rear compartment lid lock cylinder gasket. When installing on Chvrolet brands, they replace the rear compartment lid lock cylinder gasket, and for Oldsmobile it is the rear compartment lid lock cylinder & shim. Then reinstall the two rivets, the rear compartment lid applique, and finally the rear compartment, lid lock cable assembly latch and make sure that the latch is all the way popped into the locking tabs.