how to remove the PCM

Yes, the PCM in your 1996 Cadillac Seville SLS is located below the air filter hosing. You must remove the air cleaner housing to gain access to the air inlet housing where the PCM is installed. To remove the air cleaner housing first remove the triangle shaped gusset brace and disconnect the electrical connectors. The air cleaner housing "snaps" onto the air inlet housing, Pulling up on the air cleaner housing will release it. With the air cleaner out of the way, the air inlet housing released much the same way. Pull the inlet housing up onto the radiator support and replace the retainers securing the housing closed. The electrical connectors are secured to the PCM with 7mm head screws. Please be advised that a "new" PCM will need to be programmed to your vehicle before it will start and run.