Maybe 2 hours if you've never done it before and you gotta fight with the upper plenum cover to get it off. Replace the plenum gasket and retorque it correctly.
Just lube em up with silicon and make sure they're seated all the way down into their fittings when you put on and bolt the fuel rails back down. If after you hook up the connectors, you turn them towards the fuel rail then you shouldn't have any clearance problems. At least I've not seen any on any intakes I've been part of putting back together and that includes my Kenne Bell.
Yeah 2 hours seems a good estimate. make sure you have all new O-rings and that the injectors are pushed in well enough so the fuel rails bolt up perfectly.