Have done several- pretty strait forward- not a cake walk though- need to replace all the pvc hoses. use only m.b. gaskets. use the black m.b. silicone for the vent chamber.You also need to clean out the pin holes for the pvc on the chamber- very important!.
It is very easy to mess up the valve cover gaskets- you will need to be very carefull not to "loose " the gasket when you flip the v.c. over to put it back on the head. If you are not very mechanically inclined it might prove to be quite a challange.