After you put the car up on 4 jack stands all the way up:
1. Remove lower cover on the front of the tranny.
2. Remove the 4 nuts holding the converter to the flexplate.
3. Remove the tranny lines. If they're rubber, put a bolt inside the end and clamp off, if they're steel, put some plastic over the ends and rubber bands to hold it. This is just to keep all the fluid from running all over the floor out of your cooler.
4. Remove the starter from the bellhousing, I'd take the cable off as well.
5. Remove the straps off the rear u-joint and drop the rear of the shaft out of the way of the third member and pull it backwards until it's out of the back of the tranny. I like to tape some tape and wrap it around the rear u-joint to keep the free caps on. You might want to take the caps off carefully and look inside the cap and on the end of the joint to see it's condition. If it's got a zert, it'll be greasable, but if it doesn't, the only way to grease them it to disassemble them. Be very carefull not to loose the needle bearings.
6. If you don't have a rear tranny plug or an old yoke, wrap a piece of plastic around the end and zip tie it, then wrap a rag or two around the end and zip tie it as well. Remove the nuts holding the tranny to the crossmember and the nuts on the bolts holding the crossmember to the body. I like to take a small square of plywood and put it on top of my floor jack and put this under the front tranny pan, now you can remove the bolts holding the crossmember in and the crossmember. Remove the bolts holding the tranny on to the engine, most v8's have 6 although early ones had 5, I'm not sure how many I6's have, I think it's 5. Carefully slide the tranny back on the plywood making sure that the converter comes with the tranny and doesn't stay stuck on the flexplate, this way you don't have to get it set back into the front pump and won't loose any fluid. You should be able to lower the tranny now.
7. Remove the bolts holding the flexplate on and remove.
8. Put new flexplate on, there's only one way it can go on as one of the bolt holes is slightly off, so make sure they all hand start before tightening them all down. The holes for the converter should line up. Note, some converters have a drain plug installed and the new flexplate should have a corrosponding hole for the plug to go thru.
9. The rest is pretty much a reversal of taking it apart.
This is a good time to drain the fluid from the tranny, converter and cooler to replace it, also you'll need to remove the pan and replace the filter in the pan, but you don't have to do this step. Conventional wisdom has held that if you do regular fluid changes on any tranny, do it religiously, but if you neglect it, don't start doing it as stuff usually comes loose and plugs up the valve body, it doesn't take much, plus then they tend to leak, but most people have held that a C4 tends to be a leaker anyway.
