Note: If replacing Harmonic Balancer
I have heard of people having the same problem with Haynes manual as I did with Chilton. For my 95 lesabre, replacing the Harmonic balancer was a nice learning experience. Chilton manual refers to the balancer as crankshaft vibration damper. It also told me I could pull it off by hand, slap the new one on there and tighten it up. Bad Idea. Be sure to get the right kind of puller, installer, and put some oil on it. Oh yeah. And make darn sure the new one they give you at the store is the correct one. Carquest sold me one that looked like it had been installed and then removed as a "brand new part". And, it was not the right one, glad I looked it over before I drove away from the store.
For us beginners, to put it in light terms, this is important info I would have liked to have. Oh yeah, use a screwdriver or something to stop the flexplate. Chilton does show that part. There is a little cover right snug against the oil pan, 2 screws, pops right out, and be sure not to strip them on the way back in (like I did). That will keep the darn thing from turning when trying to tighten.