I have never changed the spark plugs in my 05 GT (85K miles). The covers on the plugs look like they are held in place with screws. I don't want to break them. Do they just screw out to remove the plugs.

 

You better take your car to a really good mechanic for this job. The 2005 GT's have the stock 2 piece plugs which have a tendency to break under the best of circumstances. I can't believe you have gone that far without changing plugs at all. If you have a plug break, you are looking at a really expensive bill because they need a special tool to get the rest of the plugs out.

I changed my plugs out at 5500 miles because I was so worried that if I put any extra mileage on, they would get seized in and would break later when I tried to change them. I took it to my mechanic and luckily none broke. I replace them with Champion #7989 one-piece plugs so that I will never have to worry about them breaking again. Do yourself a favor and get one piece plugs and have a really good mechanic do the job.