No offense, but if you lack the mechanical skills to get the inspection cover off, I think you will be better off letting someone else change your starter.
But since you asked, I'll help all I can. Don't get mad if these directions seem too simple. My camera won't take a useful picture that close. But I just went out to look at my car and here is what I see.
The inspection cover on my car is plastic. It makes a different sound when you tap on it than metal. As far as I can tell, the inspection cover is the only thing near the starter that is plastic, except the solenoid cover attached to the starter. Do not tap on the solenoid cover or you will break it, if you haven't broken it already with your tire iron. So if you take your ratchet wrench under there and tap around the starter lightly, the part that makes a dull thud sound when you tap on it is most likely the inspection cover. The four bolts that hold this part on are easily visible on my car. It should be evident which bolts need to be taken off. You may need to clean the area around the starter of oily road grime to identify the correct bolts. One bolt is directly below the front starter bolt at the bottom of the starter pointing towards the front of the car, the other three are accessed from the back side of the frame. They look like they are about 10mm or 3/8" bolt heads. Turn them counter clockwise to remove. Good luck.
1990 LE -wrong bumper