valve cover replacement

[cla67]

How much trouble is it to change the valve cover on the 3.0 gas engine E70. Had the O2 wiring harness catch fire the other day driving to work with a bunch of oil on the exhaust side of the engine. Shop thinks it is the ccv system that spewed the oil due to the below zero temps we've had here (Illinois). I was able to drive it to the shop without any issues, after dousing the fire with snow.

It is operating normal now with no leaks. I would be inclined to replace the gasket at least but not sure it would make sense to replace the cover if the leak was due to the weather. They quoted a price of $900. Seems like pretty straight forward job. Anything difficult to it should I decide to do it myself?