As Nick says...
I could probably do one in my sleep now, it takes about 2 ½ hours for me to get the dash off and heater box out.
Rave says steering column and all that as it's process from memory is to remove all the framework aswell, whereas if you just remove the top of the dash, loosen a couple of the framework bolts, and a slight bend to get the cross bar out/in then it saves a lot of time.
I would get some new closed cell foam, as the stuff on top of the heater box will almost certainly disintegrate.
A few tricks I use... With the instrument cluster out, I remove the 2 metal brackets that it screws to. They have 8mm nuts. I also remove the plastic side panel (2 screws) on the drivers side (basically the edge of the dash) as with all that removed, it makes it quicker and easier on your own to get the dash top out around the steering wheel, without damaging it.
Ducts.. I remove them and then use duct tape to reassemble then all together. Cutting them makes it quicker to remove - less bending etc... But can definitely be done with no cutting.
Hope that helps..