The very best "guide" that will help you perform most projects on your car is a factory service manual. These are available in either a CD format, or a printed manual format on ebay. A factory service manual will give you excellent instructions on how to remove and reinstall many of the parts that I will mention below.
I also want to mention that even though you're working on a 1969 Coronet 2 door hardtp if I remember correctly, any of the information that refers to 1966 and 1967 Charger's and Coronet's will be the same basic work needed on your 1969 Coronet. The individual parts will look different from one model year to another, but the removal process will be very similar when working with the 1966 through 1970 B-Body cars.
With that being said, removing the complete dashboard assembly is not an easy process on our older Mopars due to how they are bolted into the body and even the factory service manuals do not cover the complete process involved, because it's not something that is done very often, especially back when these cars were newer and being serviced at Chrysler dealerships. If you feel like you must remove the complete dash assembly, here are some of the major steps that will be required and more may be required depending on how your specific Coronet is optioned.
I would also highly recommend that if you do go through all of the work to remove the complete dash assembly, remove it as a complete unit, rather than taking it apart piece by piece inside of the car, as once the complete assembly is out of the car, you will then be able to take lots of digital pictures to document where each and every part is located and how each part is attached to the dash shell.
Another really helpful tip, is to document EVERY nut, bolt, washer and part as you remove it from the dash shell. Also do yourself a huge favor and buy a few boxes of various small to large sized plastic zip-lock baggies to put as many of your dash parts into as possible. Trust me, if you do not do this, you WILL forget where some of those piles of unmarked and undocumented parts go when you are ready to reassemble your dash.
Here are some of the major steps you will need to do to remove your complete dashboard assembly.
(1) Remove all of the inside front windshield and A-pillar moulding trim. (this is covered in the factory service manual)
(2) Unbolt and lower the steering column assembly down from the dashboard assembly. (this is covered in the factory service manual)
(3) Remove, or disconnect all misc parts that are attached to the dash assembly and other parts of the car, such as the speedometer cable, all wiring harnesses, fresh air vent cables, etc.
(4) Remove front bench, or bucket seats. This is not absolutely required, but it will give you much easier access to work on the dash assembly and moulding trim. (this is covered in the factory service manual)
(5) Some heater and factory air conditioning duct work and other misc parts may need to be removed, or disconnected depending on how your car is equipped. (this should all be covered in the factory service manual)
(6) Remove all exterior windshield moulding trim. (this is covered in the factory service manual)
(7) Remove the front windshield glass. (this is covered in the factory service manual, but I'd recommend having a professional glass company do this for you if your windshield glass is in good condition and you will be reusing it)
(8) Remove the front windshield gasket. This gasket is usually not reusable, so you will need to purchase a new aftermarket replacement gasket. (removal of this gasket is covered in the factory service manual)
(9) With the front windshield glass and gasket removed, you should now be able to see and remove all of the fasteners that hold the dash assembly in the car. This is not covered in the factory service manual, but below are a couple of pictures of a friends 1967 Charger after he had removed all of the above parts. If you look closely, you can see some of the fasteners that hold the dash shell to the cowl area. 1966 and 1967 Chargers do not have identical dashboard assemblies to either the 1966 or 1967 Coronets which are also slightly different from 1966 to 1967 and your 1969 Coronet will have different looking dash parts, but as far as removing the dashboard assemblies go, all of the 1966 through 1970 B-Body cars are very similar, so if you would like to follow the extensive restoration work being done on this 1967 Charger, here is the link where you can check it out.
http://www.mymopar.com/forums/index.php?showtopic=15968
Another picture with the dash assembly removed.
I hope this information helps you, but please do yourself a favor and go purchase a copy of the factory service manual for your car before you do anything else.
Ebay auction link for a 1969 Charger, Coronet and Dart factory service manual in a printed book format.
http://www.ebay.com/itm/360643479524?ssP...1438.l2648
Ebay auction link for a 1969 Charger, Coronet, Dart, Polara and Monaco factory service manual in a CD format.
http://www.ebay.com/itm/160935785596?ssP...1438.l2648
Richard.