It's just as much of a PITA to pull the muffler as it is to go thru the license plate area. I just go done with replacing all four bulbs in my 87 (they were originals!!) when I was wiring up a connection for lights for my tire trailer.
My bulbs still had all of the grease that the factory used to seal moisture out of the bulb housing. It had dried up to the point where the glass bulb twisted out of its base when I tried to pull the bulbs. Being original bulbs, I figured that if I replaced them all at once, I might be able to forego having to replace bad bulbs later on.
It really isn't too hard to do the removing but skinny arms are a big plus. First, remove the license plate and then remove the backup lamp housing. You can reach inside through the plate opening to twist the bulb holder and pull it out of the way. The holders have a plastic lock that must be depressed in order to turn it. Then reach in again and remove the two 10mm bolts that hold the inboard lamp housings. Use a 1/4 drive ratchet and socket. These bolts are not real tight so they came out easily.
Once you have the inboard lamp housing out, you can easily reach through that hole to the outboard housing and twist the bulb holder to remove the offending bulb. Then reassemble everything in the reverse order.
There are some sharp edges behind the facsia so expect some scratches on your arms. I tried to wear a long-sleeve shirt but the sleeve just got hung up on things. Figure on 1 beer per side....
