What a joke!

I said after the AC's we'd probably have time to do the cellular kit, Ha, Ha, Ha!!
Rick, the campground owner gave us invaluable help in getting the units on the roof.  It was a bit of a struggle but only took a few minutes.  There was no way Jan and I would have been able to get them up there by ourselves!
We knew the first one would take awhile as Dometic doesn't send any documentation at all because their stance is only licensed service technicians should be doing this work and they don't need any help. So I really wanted to take our time.   We first had to drop the ceiling panel and get to the bottom of the AC unit.

AC access

Then we were very careful to make sure we noted the exact wiring connections.

Good to go.  These AC units are held on the roof by 4 long bolts that go up into the unit from inside the motorhome.  They are just squeezed into place on a fairly firm gasket material that keeps the rain water outside.  Pretty simple arrangement.  After removing the bolts, we went up and pulled up on the AC unit, and nothing, stuck fast to the roof.  First glitch of the morning.  We had to pry it up and cut into the gasket material to get it free from the roof.  Finally got it off, then had to clean the roof up and get all the old gasket material off that had stuck to the roof.  We flipped the old unit over, and then set the new flipped over unit next to it, so we could modify it to fit our motorhome.  Monaco, our manufacturer had installed little cups on each side of the AC to collect the condensate so it then runs down through a hose to below the motorhome.  This is a nice touch, without it all the water the unit produces runs down over the side.  Because of these cups, we had to alter the gasket, mount the cups, and then add an extra gasket.  Also, since our motorhome has what's called a ducted AC system we had to mount a flange that directs the cool air into the ductwork in the coach.  Not too bad actually.  Then you flip it over, carefully align it with the hole in the roof, go down and tighten the 4 bolts, reconnect all the wires.  Another part of the puzzle, our system is 5 years old, the age of our motorhome, so Dometic has improved their products in the meantime, and has made our new AC's incompatible with our present thermostats.  So, since our front AC has it's own thermostat, we replaced our old one with the new whizbang one from Dometic.  It's actually pretty cool as it is programable, something we have wanted for awhile.  So, of course the new thermostat has different mounting requirements so we had to modify that as well.  We got it all hooked up, new thermostat installed, let's try it out.  We go to turn on the thermostat and no power at all!  What?  I check all my connections, press a few buttons, and nothing.  Jan has a great thought and goes to the other thermostat, guess what no power there either??????  What could we have done?  We touched nothing that had anything to do with the other thermostat.  After much hair pulling, I found a 2 amp fuse had blown for the AC control.  Replace the fuse, and boom, the nicest cold, cold air is blowing.  Yippee!  The catch, it's 4pm.  So much for doing both AC's and then the cell amp.
Our new baby.

All mounted and working!

We also took about an hour to alter the other unit.  As I said the new units are not compatible with the older thermostat, so I got a conversion kit, where you have to replace the circuit board from the new unit so it can talk to the old thermostat.  So now it's all ready to go for tomorrow.

All to be replaced.

Rain is forecast for this evening so we have the new unit and the old unit still on the roof all covered up, so we'll be ready to get the rear AC replaced first thing tomorrow morning.

Looking aft at the middle AC that is staying

So maybe tomorrow after we get the other one replaced, and the bad ones off the roof, maybe we actually will have time to tackle the cellular kit.  Keep your fingers crossed.