Unfortunately, our engines are *not* easy to work on.
Have you tried pulling the turbo to get access to the valve covers? It comes out fairly easily. You'll likely need to remove the air filter housing and ducting to get a clear shot at the drivers side cover. I've never had to remove valve covers so I'm not much help there. At least you'll be working in out of the weather, but it helps to be a bit of a contortionist.
I think Sdwarf had to pull his 7.3L for a rebuild. Maybe he will chime in. That sucker weighs over 900 lbs (the engine, not Sdwarf).