Pulling the tank off for best accessability. Airbox and couple upper fair mount plates. All clear to remove the valve cover. There number of smaller ring gaskets, can re-use them, but they get lost easy.
Estimating the time, I'm slow and two hours would be as fast as can do it.
Trick is to put the gasket in the cover groove first. Then mount the cover on the head. There some sealer used on the round notched sections on the head. Sealer on it first keeps things cleaner when manipulating the cover in place.
It's not much more doing a valve job with the cover off.
Valve cover gasket is a rubber type. Can re-use it. Cover and head have very good mated surfaces. Leaking wouldn't occure easily. I get a leak like drip from using too much chain lube. It heats up on the crankcase drips down the side and drips at the oil drain plug.
The potentially most suseptable oil leaks is the small ring seals used on the oil cooler lines. Busa has a problematic oil seal on the stator cover. Paper gasket with +/- 3/4" sealer on the crankcase butt joints. Fix is new gasket with 360 degrees of sealer on both sides of the gasket.
Anyrate goodluck