I am trying to take the dash out of my 68 charger. There is some rust up underneath the dash and a bunch of crud from 40 years of life on the road. Is this an easy job? Does anyone know of a book or an article somewhere that describes how to take everything apart?

I wouldn't call it an easy job.
The windshield and seal has to come out to get access to the screws along the front edge.
The sides are held in by one bolt on each side.
Other than the obvious wires, cables and everything else.

How do you take the windshield out other than with a baseball bat?

The 1st step is to remove the outer trim.
That requires a trim molding tool.

pic from Harbor Freight Tools


After that the outer rubber seal has a lock channel rubber that must be pried out.

After that start spraying down the entire outer perimeter of the glass and seal with soapy water (for lubrication).

Next you basically push and work the glass out from the seal.

If you're lucky you can do it without breaking the glass.

That's about the easiest way I can explain it.

Good Luck!

The glass will also most likely have a ton of sealer on it and will require you to use a guitar string, piano wire or buy the glass removel tool with a cutter and handle..
I used a couple of cans of PB blaster on the last on to help disolve the glue.
NOT a fun or easy job, plan on buying a new windshield and gasket.

Is it fairly easy to find a new windshield, in case I break the old one?

Duct work? Most of that has dry rotted out. Thanks for the advice. I normally take pictures when I start to yank stuff off of the car. It took me about a year or so to realize that there is very little that I can do to the car in a weekend. I used to think that I could do every thing in a weekend. Now, I realize that it all takes time and that it is better to try and do things right the first time. Case and point, I pulled the carpet up to change and noticed the floor pans are in worst shape than I thought. So I ripped out pretty much all of the interior of the car in order to check for more rust. Everything looks good with the exception of some surface rust spots back of the dash and a couple of very rust spots back of the dash. Also, the dash is the only part of the car that has never been painted. So, I figure as long as I have the inside mostly apart, I just as soon take the dash off, try and clean up some of the rust behind it and then paint the dash. That way, when I put the interior back in, I want have the urge to take the dash out because the rust in the back of it is bugging me.

I learned my lesson swapping out the 360 that came in the charger for a 440....more work than I thought...but it is worth it.

If the car is a non a/c car there is no need to remove heater box to get dash out. You may be able to get it of an a/c car without removal as well but I am not certain. Just disconnect the defrost tubes and heater control cables. The dash will lift out over the heater box.