how to replace spark plugs on 1999 mercury sable?

Watch a youtube video

Replacing spark plugs is easy (unless they're really hard to get to). I was able to do it myself. The only thing I needed that I didn't have a was a tool from O'Reilly's, that I used once and returned. Get some of that goop they sell by the register, and coat the threads with them.

Betty,

There are SO many ways you can screw up an engine when working on one without any experience, it's usually best to let a mechanic do the job.

If you MUST do it yourself, look up a youtube video and follow it closely.

I had a Honda with a transverse mounted V6 engine, and the 3 plugs in the rear could not be seen. I had to remove the coils and plugs by FEEL, as I couldn't see back there. No fun.

youtube video

You need a ratchet handle, and the correct size spark plug socket.

Replace them one at a time as to not get the plug wires crossed. Put anti-seize compound on the threads of each plug before installing. Do not over tighten. Most plugs today are pre-gapped, but ask to make sure.