This procedure is much the same on all years of Celebrities.
First drain the coolant into a suitable container
On the firewall locate the two hoses that go into and out of the hearer core and remove them. There should also be rubber insulators on the inlet and outlet of the heater core, save them for the new heater core.
Inside the vehicle remove the under dash cover. Locate the heater duct. It has a number of small screws plus clips that hold it in place, remove them. The duct should then be removed. There is also a small cover over the heater core inlet/outlet tubes. It is held on with three screws, one of which is a little hard to see, remove them and take off the small cover. It may be "glued" in place by a tar like insulating material. The heater core is held in place by two strap clamps over it which are held on with two screws in each. Remove the screws and clamps. The heater core will now come out
Reverse the procedure to install the new heater core. Refill the coolant and check for leaks.
Does your 1986 Chevy Celebrity have the 2.5L 4 cylinder engine or the 2.8L V6?
The heater core has failed and is leaking engine coolant.
I found one source that says a 1986 Chevy Celebrity has a curb weight of 2714 pounds. Different options would change that weight.
The spark plug gap for a 1986 Chevy Celebrity with the 2.5L 4 cyl engine is .060".
To change the front blinker bulb on your 1986 Chevy Celebrity simply reach up behind the bumper and unplug the socket from the fixture. Replace the bulb in the socket and plug the socket back into the fixture.
If it is a 2.8 it has 2
To change the headlight bulb on your 1986 Celebrity: 1. Take out the screws and remove the headlight door. 2. Remove the screws and take out the retainer that holds the bulb in place. 3. Pull the headlamp bulb out enough to unplug the wires. Install the new bulb in the reverse order.
Replace the seat belt.
Please clarify your question as in front or rear axle.
On the V6 the ignition module is under the distributor cap.
These are typically easy to changed first take off the pulley then you will have access to the bolts they behind the pulley
To change the alternator in your 1986 Chevrolet Celebrity: 1, Remove the battery ground cable. 2. Unplug remove the wiring from the alternator. 3. Loosen the bolts that hold the alternator in place. Remove the drive belt. 4. Remove the bolts and the alternator will pull out. Reverse the process to reinstall the new alternator.